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Prefixes & suffixes

157 prefixes and suffixes with their meanings and examples, plus the number prefixes, the ways English says “not”, and why in- turns into im-, il- and ir-.

Number prefixes: Latin and Greek side by side

English borrowed counting prefixes from both languages, which is why a two-wheeler is a bicycle (Latin) but a two-way choice is a dilemma (Greek). Latin sets tend to go with Latin roots and Greek with Greek, though modern coinages mix them.

Number prefixes from Latin and Greek
MeaningLatinGreek
oneuni- unicycle, uniformmono-, mon- monologue, monotone
twobi- bicycle, bilingualdi- dioxide, dilemma
threetri- triangle, tricycletri- triangle, tricycle
fourquadr-, quadri-, quadru- quadrilateral, quadrupletetra- tetrahedron, tetralogy
fivequint-, quinque- quintet, quintupletpenta- pentagon, pentathlon
sixsext-, sexa- sextet, sextanthexa- hexagon, hexameter
sevensept-, septem-, septi- September, septethepta- heptagon, heptathlon
eightoct-, octo-, octa- octopus, octagonoct-, octo-, octa- octopus, octagon
ninenona-, novem- nonagon, nonagenarianno common prefix
tendeci- decimal, decimeterdeca- decade, decagon
hundredcent-, centi- century, centipedehecto- hectare, hectometer
thousandmilli-, mill- millennium, millimeterkilo- kilogram, kilometer
halfsemi- semicircle, semifinalhemi- hemisphere, hemicycle
manymulti- multiply, multimediapoly- polygon, polyglot
allomni- omnivore, omnipotentpan-, panto- panorama, pandemic

Negative prefixes: not, without, against

Un- is native English and goes on almost anything; in- came with Latin words and usually stays on them; a- or an- is the Greek ‘without’; non- is a plain ‘not’. That is how English ends up with unable but inability, and amoral (outside morality) next to immoral (against it).

Prefixes that mean not, against or wrongly
PrefixMeaningFromExamples
un-not; the reverse ofOld Englishunhappy, unable, undo
in-, im-, il-, ir-not, withoutLatininactive, incredible, impossible
non-notLatinnonsense, nonfiction, nonstop
a-, an-not, withoutGreekatypical, amoral, anonymous
dis-, dif-apart, away; not, the opposite ofLatindisagree, dissect, disappear
anti-, ant-against, opposite ofGreekantibiotic, antisocial, antidote
contra-, contro-, counter-against, oppositeLatincontradict, contrary, controversy
mis-wrongly, badlyOld Englishmisspell, mistake, misunderstand
de-down, away, off; reverse or removeLatindescend, deflate, detach
mal-, male-bad, badlyLatinmalfunction, malnutrition, malevolent

Assimilation: why in- becomes im-, il- and ir-

Many Latin prefixes end in a consonant that changed to match the next sound, which made words easier to say: in + possible became impossible, ad + tract became attract. The prefix is the same; only its last letter moved. Spotting this helps with spelling double letters: accommodate, immediate and irregular each double a consonant at the join.

in- ‘not’ Latin Wiktionary: in-
SpellingBeforeExamples
im-b, m, pimbalance immature impossible
il-lillegal illogical illiterate
ir-rirregular irresponsible irrational
in-other lettersinactive incredible invisible
in- ‘in, into’ Latin Wiktionary: in-
SpellingBeforeExamples
im-b, m, pimmigrate import imbibe
il-lilluminate illustrate
ir-rirrigate irradiate
in-other lettersinclude inject inspect
com- ‘with, together’ Latin Wiktionary: com-
SpellingBeforeExamples
com-b, m, pcombine commit compose
col-lcollect collapse
cor-rcorrespond correct
co-vowels and hcooperate coexist cohere
con-other lettersconnect construct contain
ad- ‘to, toward’ Latin Wiktionary: ad-
SpellingBeforeExamples
ac-c, qaccept acquire
af-faffix affirm
ag-gaggressive aggregate
al-lallocate allude
an-nannex announce
ap-pappoint apply
ar-rarrive arrogant
as-sassist assume
at-tattract attend
a-sc, sp, stascend aspire
ad-other lettersadhere adjacent advocate
ex- ‘out’ Latin Wiktionary: ex-
SpellingBeforeExamples
e-b, d, g, j, l, m, n, r, vemit eject evade
ef-feffect efficient
ex-vowels, c, p, t and othersexit export extract
ob- ‘toward, against’ Latin Wiktionary: ob-
SpellingBeforeExamples
oc-coccur occasion
of-foffend offer
op-poppose oppress
ob-other lettersobject obstruct obtain
sub- ‘under’ Latin Wiktionary: sub-
SpellingBeforeExamples
suc-csucceed
suf-fsuffix suffocate
sug-gsuggest
sup-psupport suppress
sur-rsurrogate
sus-c, p, tsuspend sustain
sub-other letterssubmarine submit subtract
syn- ‘together, with’ Greek Wiktionary: syn-
SpellingBeforeExamples
sym-b, m, psymbol symmetry sympathy
syl-lsyllable
sy-s plus a consonantsystem
syn-other letterssynonym synthesis synchronize
dis- ‘apart, not’ Latin Wiktionary: dis-
SpellingBeforeExamples
dif-fdiffer diffuse
di-some consonants such as l, vdilute divert
dis-other lettersdisagree dismiss dissect

All prefixes & suffixes

Showing all 157 prefixes and suffixes

  1. a-, an- prefix · Not & against

    not, without

    [Greek ἀ- (a-), ἀν- (an-) ‘not, without’]

    atypical · amoral · anonymous · anarchy · apathy

    Wiktionary: a-, an-
  2. ab-, abs- prefix · Place & direction

    away, from

    [Latin ab ‘away from’]

    absent · abduct · abnormal · abstract · avert

    Wiktionary: ab-, abs-
  3. -able, -ible suffix · Makes adjectives

    able to be, worth being

    [Latin -ābilis, -ibilis, through French]

    readable · comfortable · incredible · visible · flexible

    Wiktionary: -able, -ible
  4. ad- (ac-, af-, ag-, al-, an-, ap-, ar-, as-, at-) prefix · Place & direction

    to, toward

    [Latin ad ‘to, toward’]

    adhere · accept · affix · allocate · attract

    Wiktionary: ad- (ac-, af-, ag-, al-, an-, ap-, ar-, as-, at-)
  5. -al suffix · Makes adjectives

    relating to; the act of

    [Latin -ālis]

    natural · musical · personal · arrival · refusal

    Wiktionary: -al
  6. ambi- prefix · Place & direction

    both, around

    [Latin ambi- ‘around, on both sides’]

    ambiguous · ambidextrous · ambivalent · ambient

    Wiktionary: ambi-
  7. amphi- prefix · Place & direction

    both kinds, on both sides, around

    [Greek ἀμφί (amphí) ‘on both sides, around’]

    amphibian · amphitheater · amphibious

    Wiktionary: amphi-
  8. ana- prefix · Place & direction

    up, back, again

    [Greek ἀνά (aná) ‘up, back, again’]

    analysis · anatomy · anachronism · anagram

    Wiktionary: ana-
  9. -ance, -ence, -ancy, -ency suffix · Makes nouns

    state, quality or action

    [Latin -antia, -entia, through French]

    performance · independence · assistance · existence · fluency

    Wiktionary: -ance, -ence, -ancy, -ency
  10. ante- prefix · Time & order

    before

    [Latin ante ‘before’]

    antecedent · anteroom · antedate · antebellum

    Wiktionary: ante-
  11. -ant, -ent suffix · Makes words for people

    doing; a person or thing that does

    [Latin present participle -āns, -ēns (-antem, -entem)]

    assistant · servant · student · resident · different

    Wiktionary: -ant, -ent
  12. anti-, ant- prefix · Not & against

    against, opposite of

    [Greek ἀντί (antí) ‘against, opposite’]

    antibiotic · antisocial · antidote · antonym · antacid

    Wiktionary: anti-, ant-
  13. apo- prefix · Place & direction

    away from, off

    [Greek ἀπό (apó) ‘away from’]

    apology · apostrophe · apostle · apogee

    Wiktionary: apo-
  14. -ar suffix · Makes adjectives

    relating to, like

    [Latin -āris]

    solar · lunar · circular · muscular · popular

    Wiktionary: -ar
  15. -arium, -orium suffix · Makes nouns

    a place for

    [Latin -ārium, -ōrium]

    aquarium · auditorium · planetarium · sanatorium

    Wiktionary: -arium, -orium
  16. -ary suffix · Makes adjectives

    relating to; a place or collection

    [Latin -ārius, -ārium]

    library · dictionary · primary · documentary · solitary

    Wiktionary: -ary
  17. -ate suffix · Makes verbs

    to make or act on; having, full of

    [Latin -ātus, past participle ending of verbs in -āre]

    activate · celebrate · fortunate · passionate · separate

    Wiktionary: -ate
  18. -ation, -ition suffix · Makes nouns

    the act, process or result of

    [Latin -ātiō, -ātiōnis]

    creation · transportation · imagination · competition

    Wiktionary: -ation, -ition
  19. auto- prefix · Manner & quality

    self, by itself

    [Greek αὐτός (autós) ‘self’]

    automatic · autobiography · autograph · autonomy

    Wiktionary: auto-
  20. be- prefix · Manner & quality

    thoroughly; to make or treat as

    [Old English be- (from bī ‘by, near’)]

    befriend · belittle · bewitch · becalm

    Wiktionary: be-
  21. bene- prefix · Manner & quality

    well, good

    [Latin bene ‘well’]

    benefit · benevolent · benediction · beneficial

    Wiktionary: bene-
  22. bi- prefix · Number

    two, twice

    [Latin bi- ‘twice, double’ (from bis)]

    bicycle · bilingual · binoculars · bisect · biannual

    Wiktionary: bi-
  23. cata-, cat- prefix · Place & direction

    down, against, completely

    [Greek κατά (katá) ‘down’]

    catastrophe · catalog · catapult · cataract · cathode

    Wiktionary: cata-, cat-
  24. cent-, centi- prefix · Number

    hundred; one hundredth

    [Latin centum ‘hundred’]

    century · centipede · centimeter · percent · centennial

    Wiktionary: cent-, centi-
  25. -cide suffix · Science & fields of study

    killing; killer

    [Latin -cīda, -cīdium, from caedere ‘to kill’]

    pesticide · homicide · insecticide · genocide

    Wiktionary: -cide
  26. circum- prefix · Place & direction

    around

    [Latin circum ‘around’]

    circumference · circumnavigate · circumstance · circumvent

    Wiktionary: circum-
  27. -cle, -cule suffix · Makes nouns

    small

    [Latin -culus, -cula, -culum]

    particle · molecule · minuscule · corpuscle

    Wiktionary: -cle, -cule
  28. com-, con-, col-, cor-, co- prefix · Together & apart

    with, together; thoroughly

    [Latin cum ‘with’ (com- and con- in compounds)]

    combine · connect · collect · correspond · cooperate

    Wiktionary: com-, con-, col-, cor-, co-
  29. contra-, contro-, counter- prefix · Not & against

    against, opposite

    [Latin contrā ‘against’ (counter- through French)]

    contradict · contrary · controversy · counteract

    Wiktionary: contra-, contro-, counter-
  30. -cracy, -crat suffix · Science & fields of study

    rule, government; one who rules or supports a kind of rule

    [Greek -κρατία (-kratía), from κράτος (krátos) ‘power, rule’]

    democracy · aristocracy · autocracy · bureaucrat · democrat

    Wiktionary: -cracy, -crat
  31. de- prefix · Place & direction

    down, away, off; reverse or remove

    [Latin dē ‘down from, away’]

    descend · deflate · detach · decode · deduct

    Wiktionary: de-
  32. deca- prefix · Number

    ten

    [Greek δέκα (déka) ‘ten’]

    decade · decagon · decathlon · decapod

    Wiktionary: deca-
  33. deci- prefix · Number

    one tenth; ten

    [Latin decimus ‘tenth’, decem ‘ten’]

    decimal · decimeter · decibel · decimate

    Wiktionary: deci-
  34. di- prefix · Number

    two, double

    [Greek δι- (di-), from δίς (dís) ‘twice’]

    dioxide · dilemma · diphthong · dipole

    Wiktionary: di-
  35. dia- prefix · Place & direction

    through, across, apart

    [Greek διά (diá) ‘through’]

    diagonal · diameter · dialogue · diagnosis · diorama

    Wiktionary: dia-
  36. dis-, dif- prefix · Not & against

    apart, away; not, the opposite of

    [Latin dis- ‘apart, asunder’]

    disagree · dissect · disappear · differ · dismiss

    Wiktionary: dis-, dif-
  37. -dom suffix · Makes nouns

    state, condition; realm

    [Old English -dōm]

    kingdom · freedom · wisdom · boredom

    Wiktionary: -dom
  38. dys- prefix · Manner & quality

    bad, difficult, abnormal

    [Greek δυσ- (dus-) ‘bad, hard’]

    dysfunction · dyslexia · dystopia · dyspepsia

    Wiktionary: dys-
  39. -ectomy suffix · Science & fields of study

    surgical removal

    [Greek ἐκτομή (ektomḗ) ‘a cutting out’]

    appendectomy · tonsillectomy · mastectomy

    Wiktionary: -ectomy
  40. -ee suffix · Makes words for people

    a person who receives or undergoes

    [French -é, from Latin -ātus]

    employee · trainee · refugee · nominee

    Wiktionary: -ee
  41. endo- prefix · Place & direction

    within, inside

    [Greek ἔνδον (éndon) ‘within’]

    endoscope · endocrine · endothermic · endoskeleton

    Wiktionary: endo-
  42. en-, em- prefix · Manner & quality

    to put into; to make, cause to be

    [Latin in- ‘in, into’, through French en-]

    enable · enclose · encourage · empower · embrace

    Wiktionary: en-, em-
  43. en-, em- (Greek) prefix · Place & direction

    in, within

    [Greek ἐν (en) ‘in’]

    energy · empathy · emphasis · enthusiasm

    Wiktionary: en-, em- (Greek)
  44. epi-, ep- prefix · Place & direction

    on, upon, over, after

    [Greek ἐπί (epí) ‘upon, over’]

    epidermis · epidemic · epilogue · epicenter · epitaph

    Wiktionary: epi-, ep-
  45. -escent, -escence suffix · Makes adjectives

    becoming, beginning to be

    [Latin -ēscēns, present participle of verbs in -ēscere]

    adolescent · fluorescent · effervescent · convalescent

    Wiktionary: -escent, -escence
  46. -esque suffix · Makes adjectives

    in the style of

    [French -esque, from Italian -esco]

    picturesque · statuesque · Kafkaesque

    Wiktionary: -esque
  47. eu- prefix · Manner & quality

    good, well

    [Greek εὖ (eû) ‘well’]

    euphoria · eulogy · euphemism · euthanasia

    Wiktionary: eu-
  48. ex-, e-, ef- prefix · Place & direction

    out, out of; former

    [Latin ex ‘out of’ (ē- before some consonants)]

    exit · export · extract · eject · effect

    Wiktionary: ex-, e-, ef-
  49. exo- prefix · Place & direction

    outside, outer

    [Greek ἔξω (éxō) ‘outside’]

    exoskeleton · exotic · exothermic · exosphere

    Wiktionary: exo-
  50. extra- prefix · Place & direction

    outside, beyond

    [Latin extrā ‘outside’]

    extraordinary · extraterrestrial · extracurricular · extravagant

    Wiktionary: extra-
  51. fore- prefix · Time & order

    before, in front

    [Old English fore ‘before’]

    forecast · forehead · foresee · foreword

    Wiktionary: fore-
  52. -ful suffix · Makes adjectives

    full of; the amount that fills

    [Old English -full]

    hopeful · careful · wonderful · spoonful

    Wiktionary: -ful
  53. -fy, -ify suffix · Makes verbs

    to make, to become

    [Latin -ficāre, from facere ‘to make’, through French -fier]

    simplify · magnify · clarify · purify · terrify

    Wiktionary: -fy, -ify
  54. -graphy suffix · Science & fields of study

    writing, recording or describing; a field of study

    [Greek -γραφία (-graphía), from γράφειν (gráphein) ‘to write’]

    biography · geography · photography · calligraphy

    Wiktionary: -graphy
  55. hecto- prefix · Number

    hundred

    [Greek ἑκατόν (hekatón) ‘hundred’, through French]

    hectare · hectometer · hectopascal

    Wiktionary: hecto-
  56. hemi- prefix · Number

    half

    [Greek ἡμι- (hēmi-) ‘half’]

    hemisphere · hemicycle · hemiplegia

    Wiktionary: hemi-
  57. hepta- prefix · Number

    seven

    [Greek ἑπτά (heptá) ‘seven’]

    heptagon · heptathlon · heptameter

    Wiktionary: hepta-
  58. hetero- prefix · Manner & quality

    other, different

    [Greek ἕτερος (héteros) ‘other’]

    heterogeneous · heteronym · heterodox

    Wiktionary: hetero-
  59. hexa- prefix · Number

    six

    [Greek ἕξ (héx) ‘six’]

    hexagon · hexameter · hexapod

    Wiktionary: hexa-
  60. homo-, homeo- prefix · Manner & quality

    same, alike

    [Greek ὁμός (homós) ‘same’]

    homogeneous · homonym · homophone · homograph

    Wiktionary: homo-, homeo-
  61. -hood suffix · Makes nouns

    state or time of being

    [Old English -hād ‘state, rank’]

    childhood · neighborhood · adulthood · brotherhood

    Wiktionary: -hood
  62. hyper- prefix · Size & degree

    over, above, beyond, too much

    [Greek ὑπέρ (hupér) ‘over, beyond’]

    hyperactive · hyperbole · hypertension · hyperventilate

    Wiktionary: hyper-
  63. hypo-, hyp- prefix · Size & degree

    under, below, less than normal

    [Greek ὑπό (hupó) ‘under’]

    hypothermia · hypodermic · hypothesis · hyphen

    Wiktionary: hypo-, hyp-
  64. -ia suffix · Science & fields of study

    condition, state; place

    [Greek and Latin -ia, a noun ending]

    insomnia · nostalgia · anemia · utopia

    Wiktionary: -ia
  65. -ian, -ician, -arian suffix · Makes words for people

    relating to; a person skilled in

    [Latin -iānus]

    musician · librarian · historian · pediatrician

    Wiktionary: -ian, -ician, -arian
  66. -ic, -ical suffix · Makes adjectives

    relating to, characteristic of

    [Greek -ικός (-ikós), Latin -icus]

    historic · athletic · poetic · scientific · musical

    Wiktionary: -ic, -ical
  67. -ics suffix · Science & fields of study

    a field of study or practice

    [Greek -ικά (-iká), plural of -ικός]

    physics · economics · athletics · politics

    Wiktionary: -ics
  68. -id suffix · Makes adjectives

    having a quality, in a state

    [Latin -idus]

    vivid · rapid · fluid · lucid · timid

    Wiktionary: -id
  69. -ile suffix · Makes adjectives

    able to; relating to

    [Latin -ilis]

    fragile · mobile · juvenile · docile · tactile

    Wiktionary: -ile
  70. -ine suffix · Makes adjectives

    relating to, like

    [Latin -īnus]

    canine · feline · marine · equine

    Wiktionary: -ine
  71. infra- prefix · Place & direction

    below, beneath

    [Latin īnfrā ‘below’]

    infrared · infrastructure · infrasound

    Wiktionary: infra-
  72. in-, im-, il-, ir- (into) prefix · Place & direction

    in, into, on, toward

    [Latin in ‘in, into’]

    include · inject · import · illuminate · irrigate

    Wiktionary: in-, im-, il-, ir- (into)
  73. in-, im-, il-, ir- (not) prefix · Not & against

    not, without

    [Latin in- ‘not, un-’]

    inactive · incredible · impossible · illegal · irregular

    Wiktionary: in-, im-, il-, ir- (not)
  74. inter- prefix · Place & direction

    between, among

    [Latin inter ‘between’]

    international · interrupt · intersect · interval

    Wiktionary: inter-
  75. intra-, intro- prefix · Place & direction

    within, inward

    [Latin intrā ‘within’, intrō ‘inwardly’]

    intravenous · intramural · introvert · introduce

    Wiktionary: intra-, intro-
  76. -ion, -tion, -sion suffix · Makes nouns

    the act, process or result of

    [Latin -iō, -iōnis]

    action · decision · invention · mission · union

    Wiktionary: -ion, -tion, -sion
  77. -ish suffix · Makes adjectives

    somewhat; like; of a nation

    [Old English -isc]

    childish · reddish · foolish · English

    Wiktionary: -ish
  78. -ism suffix · Makes nouns

    belief, practice or condition

    [Greek -ισμός (-ismós), through Latin and French]

    heroism · criticism · realism · tourism · magnetism

    Wiktionary: -ism
  79. -ist suffix · Makes words for people

    a person who does, practises or believes

    [Greek -ιστής (-istḗs), through Latin and French]

    artist · dentist · pianist · scientist · cyclist

    Wiktionary: -ist
  80. -itis suffix · Science & fields of study

    inflammation of

    [Greek -ῖτις (-îtis)]

    arthritis · tonsillitis · bronchitis · appendicitis

    Wiktionary: -itis
  81. -ity suffix · Makes nouns

    state or quality of

    [Latin -itās, -itātis, through French -ité]

    ability · curiosity · equality · reality · variety

    Wiktionary: -ity
  82. -ive, -ative, -itive suffix · Makes adjectives

    tending to, doing

    [Latin -īvus, through French -if]

    active · creative · talkative · expensive · sensitive

    Wiktionary: -ive, -ative, -itive
  83. -ize, -ise suffix · Makes verbs

    to make, to become, to do

    [Greek -ίζειν (-ízein), through Latin -izāre]

    realize · modernize · criticize · organize · sympathize

    Wiktionary: -ize, -ise
  84. kilo- prefix · Number

    thousand

    [Greek χίλιοι (khílioi) ‘thousand’, through French]

    kilogram · kilometer · kilowatt · kilobyte

    Wiktionary: kilo-
  85. -less suffix · Makes adjectives

    without

    [Old English -lēas ‘free from, without’]

    careless · hopeless · homeless · endless

    Wiktionary: -less
  86. -logy, -ology suffix · Science & fields of study

    study of, science of; speech

    [Greek -λογία (-logía), from λόγος (lógos) ‘word, reason’]

    biology · geology · psychology · zoology · technology

    Wiktionary: -logy, -ology
  87. -ly suffix · Makes adverbs

    in a certain way; like, every

    [Old English -līċe, -līċ ‘like’]

    quickly · slowly · friendly · weekly

    Wiktionary: -ly
  88. macro- prefix · Size & degree

    large, long

    [Greek μακρός (makrós) ‘long, large’]

    macroeconomics · macrocosm · macroscopic

    Wiktionary: macro-
  89. mal-, male- prefix · Manner & quality

    bad, badly

    [Latin male ‘badly’, malus ‘bad’ (through French mal)]

    malfunction · malnutrition · malevolent · malediction

    Wiktionary: mal-, male-
  90. -mania, -maniac suffix · Science & fields of study

    madness; extreme enthusiasm

    [Greek μανία (manía) ‘madness’]

    kleptomania · pyromaniac · megalomania

    Wiktionary: -mania, -maniac
  91. mega-, megalo- prefix · Size & degree

    large, great; one million

    [Greek μέγας (mégas) ‘great’]

    megaphone · megabyte · megalith · megawatt

    Wiktionary: mega-, megalo-
  92. -ment suffix · Makes nouns

    the action, result or means of

    [Latin -mentum, through French]

    government · movement · payment · statement · enjoyment

    Wiktionary: -ment
  93. meso- prefix · Place & direction

    middle

    [Greek μέσος (mésos) ‘middle’]

    Mesopotamia · mesosphere · Mesozoic

    Wiktionary: meso-
  94. meta-, met- prefix · Manner & quality

    after, beyond; change

    [Greek μετά (metá) ‘after, beyond, with’]

    metaphor · metamorphosis · metabolism · metaphysics

    Wiktionary: meta-, met-
  95. micro- prefix · Size & degree

    small

    [Greek μικρός (mikrós) ‘small’]

    microscope · microphone · microbe · microwave

    Wiktionary: micro-
  96. milli-, mill- prefix · Number

    thousand; one thousandth

    [Latin mīlle ‘thousand’]

    millennium · millimeter · million · millipede

    Wiktionary: milli-, mill-
  97. miso-, mis- (hatred) prefix · Manner & quality

    hatred, dislike

    [Greek μισέω (miséō) ‘to hate’, μῖσος (mîsos) ‘hatred’]

    misanthrope · misogyny · misology

    Wiktionary: miso-, mis- (hatred)
  98. mis- (wrongly) prefix · Not & against

    wrongly, badly

    [Old English mis- ‘wrongly’]

    misspell · mistake · misunderstand · mislead

    Wiktionary: mis- (wrongly)
  99. mono-, mon- prefix · Number

    one, single, alone

    [Greek μόνος (mónos) ‘alone, single’]

    monologue · monotone · monopoly · monarch · monorail

    Wiktionary: mono-, mon-
  100. -mony suffix · Makes nouns

    state, condition or result

    [Latin -mōnia, -mōnium]

    matrimony · testimony · parsimony · acrimony

    Wiktionary: -mony
  101. multi- prefix · Size & degree

    many

    [Latin multus ‘much, many’]

    multiply · multimedia · multicolored · multitude

    Wiktionary: multi-
  102. neo- prefix · Time & order

    new

    [Greek νέος (néos) ‘new’]

    neologism · neonatal · neoclassical · neophyte

    Wiktionary: neo-
  103. -ness suffix · Makes nouns

    state or quality of being

    [Old English -nes, -nis]

    kindness · happiness · darkness · fitness

    Wiktionary: -ness
  104. non- prefix · Not & against

    not

    [Latin nōn ‘not’]

    nonsense · nonfiction · nonstop · nonprofit

    Wiktionary: non-
  105. nona-, novem- prefix · Number

    nine

    [Latin nōnus ‘ninth’, novem ‘nine’]

    nonagon · nonagenarian · November

    Wiktionary: nona-, novem-
  106. ob- (oc-, of-, op-) prefix · Place & direction

    toward, against, in the way

    [Latin ob ‘toward, against’]

    object · obstruct · occur · offend · oppose

    Wiktionary: ob- (oc-, of-, op-)
  107. oct-, octo-, octa- prefix · Number

    eight

    [Latin octō, Greek ὀκτώ (oktṓ) ‘eight’]

    octopus · octagon · October · octave · octet

    Wiktionary: oct-, octo-, octa-
  108. -oid suffix · Makes adjectives

    like, resembling

    [Greek -ειδής (-eidḗs) ‘-like’, from εἶδος (eîdos) ‘form’]

    android · asteroid · humanoid · spheroid

    Wiktionary: -oid
  109. omni- prefix · Size & degree

    all, every

    [Latin omnis ‘all’]

    omnivore · omnipotent · omniscient · omnipresent

    Wiktionary: omni-
  110. -or suffix · Makes words for people

    a person or thing that does

    [Latin -or, -tor, -sor]

    actor · inventor · spectator · elevator · conductor

    Wiktionary: -or
  111. -ory suffix · Makes adjectives

    relating to; a place for

    [Latin -ōrius, -ōrium]

    laboratory · dormitory · observatory · sensory · memory

    Wiktionary: -ory
  112. -osis, -sis suffix · Science & fields of study

    a process, action or condition

    [Greek -ωσις (-ōsis), -σις (-sis)]

    diagnosis · hypnosis · metamorphosis · analysis · synthesis

    Wiktionary: -osis, -sis
  113. -ous, -ious, -ose suffix · Makes adjectives

    full of, having

    [Latin -ōsus, through French -eux]

    famous · dangerous · curious · generous · verbose

    Wiktionary: -ous, -ious, -ose
  114. out- prefix · Place & direction

    outside; more or better than

    [Old English ūt ‘out’]

    outrun · outlive · outdoor · outnumber

    Wiktionary: out-
  115. over- prefix · Size & degree

    above; too much

    [Old English ofer ‘over’]

    overcook · overflow · overlook · overcome

    Wiktionary: over-
  116. pan-, panto- prefix · Size & degree

    all, every

    [Greek πᾶς (pâs), neuter πᾶν (pân) ‘all’]

    panorama · pandemic · panacea · pantheon

    Wiktionary: pan-, panto-
  117. para-, par- prefix · Place & direction

    beside, alongside; beyond

    [Greek παρά (pará) ‘beside’]

    paragraph · parallel · paradox · parasite · parody

    Wiktionary: para-, par-
  118. pen-, pene- prefix · Size & degree

    almost

    [Latin paene ‘almost’]

    peninsula · penultimate · penumbra

    Wiktionary: pen-, pene-
  119. penta- prefix · Number

    five

    [Greek πέντε (pénte) ‘five’]

    pentagon · pentathlon · pentameter

    Wiktionary: penta-
  120. per- prefix · Place & direction

    through, thoroughly

    [Latin per ‘through’]

    perfect · perforate · permit · persist · perennial

    Wiktionary: per-
  121. peri- prefix · Place & direction

    around, near

    [Greek περί (perí) ‘around’]

    perimeter · periscope · period · peripheral

    Wiktionary: peri-
  122. -phobia, -phobe suffix · Science & fields of study

    fear or strong dislike of

    [Greek -φοβία (-phobía), from φόβος (phóbos) ‘fear’]

    claustrophobia · arachnophobia · xenophobia · technophobe

    Wiktionary: -phobia, -phobe
  123. poly- prefix · Size & degree

    many

    [Greek πολύς (polús) ‘much, many’]

    polygon · polyglot · polymer · polytheism

    Wiktionary: poly-
  124. post- prefix · Time & order

    after, behind

    [Latin post ‘after, behind’]

    postpone · postscript · postwar · posterior

    Wiktionary: post-
  125. pre- prefix · Time & order

    before, in front

    [Latin prae ‘before’]

    preview · predict · prepare · prefix · precede

    Wiktionary: pre-
  126. pro- (before) prefix · Time & order

    before, in front

    [Greek πρό (pró) ‘before’]

    prologue · prophet · problem · program

    Wiktionary: pro- (before)
  127. pro- (forward) prefix · Place & direction

    forward, forth; in favor of

    [Latin prō ‘forward, for’]

    proceed · produce · promote · project · propel

    Wiktionary: pro- (forward)
  128. proto-, prot- prefix · Time & order

    first, earliest

    [Greek πρῶτος (prôtos) ‘first’]

    prototype · protocol · protagonist · proton

    Wiktionary: proto-, prot-
  129. pseudo- prefix · Manner & quality

    false, fake

    [Greek ψευδής (pseudḗs) ‘false’]

    pseudonym · pseudoscience · pseudopod

    Wiktionary: pseudo-
  130. quadr-, quadri-, quadru- prefix · Number

    four

    [Latin quattuor ‘four’ (quadri- in compounds)]

    quadrilateral · quadruple · quadrant · quadrangle

    Wiktionary: quadr-, quadri-, quadru-
  131. quint-, quinque- prefix · Number

    five

    [Latin quīntus ‘fifth’, quīnque ‘five’]

    quintet · quintuplet · quintessence

    Wiktionary: quint-, quinque-
  132. re-, red- prefix · Time & order

    again; back

    [Latin re- ‘again, back’]

    return · rebuild · react · reject · revise

    Wiktionary: re-, red-
  133. retro- prefix · Time & order

    backward, back in time

    [Latin retrō ‘backward’]

    retrospect · retroactive · retrograde · retrofit

    Wiktionary: retro-
  134. se- prefix · Together & apart

    apart, aside

    [Latin sē- ‘apart, without’]

    separate · secede · secure · select · seclude

    Wiktionary: se-
  135. semi- prefix · Number

    half, partly

    [Latin sēmi- ‘half’]

    semicircle · semifinal · semiconductor · semicolon

    Wiktionary: semi-
  136. sept-, septem-, septi- prefix · Number

    seven

    [Latin septem ‘seven’]

    September · septet · septuagenarian

    Wiktionary: sept-, septem-, septi-
  137. sext-, sexa- prefix · Number

    six

    [Latin sex ‘six’, sextus ‘sixth’]

    sextet · sextant · sexagenarian

    Wiktionary: sext-, sexa-
  138. -ship suffix · Makes nouns

    state, condition or skill

    [Old English -scipe]

    friendship · leadership · citizenship · hardship

    Wiktionary: -ship
  139. -some suffix · Makes adjectives

    tending to, causing

    [Old English -sum]

    awesome · lonesome · troublesome · tiresome

    Wiktionary: -some
  140. sub- (suc-, suf-, sug-, sup-, sur-, sus-) prefix · Place & direction

    under, below; less than

    [Latin sub ‘under’]

    submarine · subway · succeed · suffix · support

    Wiktionary: sub- (suc-, suf-, sug-, sup-, sur-, sus-)
  141. super-, supra-, sur- prefix · Place & direction

    above, over, beyond

    [Latin super, suprā ‘above’ (sur- through French)]

    supervise · superior · supernatural · surpass · surname

    Wiktionary: super-, supra-, sur-
  142. syn-, sym-, syl-, sys- prefix · Together & apart

    together, with

    [Greek σύν (sún) ‘with, together’]

    synonym · symphony · sympathy · syllable · system

    Wiktionary: syn-, sym-, syl-, sys-
  143. tele- prefix · Place & direction

    far, at a distance

    [Greek τῆλε (têle) ‘far off’]

    telephone · television · telescope · telegraph · telepathy

    Wiktionary: tele-
  144. tetra- prefix · Number

    four

    [Greek τέτταρες (téttares) ‘four’ (τετρα- in compounds)]

    tetrahedron · tetralogy · tetrapod

    Wiktionary: tetra-
  145. trans- prefix · Place & direction

    across, beyond, through

    [Latin trāns ‘across’]

    transport · transfer · translate · transmit · transparent

    Wiktionary: trans-
  146. tri- prefix · Number

    three

    [Latin trēs, Greek τρεῖς (treîs) ‘three’]

    triangle · tricycle · trilogy · tripod · trio

    Wiktionary: tri-
  147. -tude, -itude suffix · Makes nouns

    state or quality of

    [Latin -tūdō, -tūdinis]

    attitude · gratitude · solitude · magnitude · altitude

    Wiktionary: -tude, -itude
  148. ultra- prefix · Size & degree

    beyond, extremely

    [Latin ultrā ‘beyond’]

    ultraviolet · ultrasound · ultramarine

    Wiktionary: ultra-
  149. un- prefix · Not & against

    not; the reverse of

    [Old English un- ‘not’]

    unhappy · unable · undo · unlock · unbelievable

    Wiktionary: un-
  150. under- prefix · Size & degree

    below; too little

    [Old English under ‘under’]

    underground · underline · underestimate · underwater

    Wiktionary: under-
  151. uni- prefix · Number

    one

    [Latin ūnus ‘one’]

    unicycle · uniform · unicorn · unify · universe

    Wiktionary: uni-
  152. -ure suffix · Makes nouns

    the act, process or result of

    [Latin -ūra]

    culture · failure · mixture · procedure · closure

    Wiktionary: -ure
  153. vice- prefix · Manner & quality

    in place of, deputy

    [Latin vice ‘in place of’]

    viceroy · vice-president · vice-chancellor

    Wiktionary: vice-
  154. -ward, -wards suffix · Makes adverbs

    in the direction of

    [Old English -weard]

    backward · toward · forward · homeward

    Wiktionary: -ward, -wards
  155. with- prefix · Not & against

    against; back, away

    [Old English wiþ ‘against’]

    withdraw · withhold · withstand

    Wiktionary: with-
  156. -y (adjective) suffix · Makes adjectives

    full of, like (forms adjectives)

    [Old English -iġ]

    rainy · sleepy · dusty · salty

    Wiktionary: -y (adjective)
  157. -y (noun) suffix · Makes nouns

    state, quality or act (forms nouns)

    [Greek and Latin -ia, through French -ie]

    geometry · monarchy · victory · sympathy · jealousy

    Wiktionary: -y (noun)

Using the list

Search by spelling (-able, sub), by meaning (not, three, small) or by a word you want to understand (misspell). Type narrows the list to prefixes or suffixes, Language to Latin, Greek or Old English, and Kind of meaning to groups such as numbers or suffixes that make adjectives. Assimilated spellings are listed under their main prefix, so im- is found under in-.

Suffixes often tell you a word’s job: -tion and -ness make nouns, -ous and -able make adjectives, -ize and -fy make verbs. Each entry links the Wiktionary page it was checked against.

Questions

Is it un- or in-?

There is no rule that always works. Un- is the native English prefix and is used freely; in- arrived inside words borrowed from Latin or French. When in doubt, check a dictionary: unable and inability are both standard.

Why is it bicycle but dilemma?

Bi- is the Latin ‘two’ and di- the Greek one. Words built in Greek, such as dilemma, keep the Greek prefix; Latin and later English coinages, such as bicycle, mostly use the Latin one.

What does assimilation mean?

A sound becoming more like its neighbour. The n of in- turns into m before b, m and p, which are made with the lips, and copies an l or r, so in + legal became illegal.