What is a Prefix?


prefix is placed at the beginning of a word to modify or change its meaning. This is a list of the most common prefixes in English, together with their basic meaning and some examples. You can find more detail or precision for each prefix in any good dictionary. The origins of words are extremely complicated. You should use this list as a guide only, to help you understand possible meanings. But be very careful, because often what appears to be a prefix is not a prefix at all. Note also that this list does not include elements like "auto-" or " bio-", because these are "combining forms", not prefixes.

a-also an-not, withoutatheist, anaemic
a-to, towardsaside, aback
in the process of, in a particular statea-hunting, aglow
ab-also abs-away, fromabdicate, abstract
ad-also a-, ac-, af-, ag- al-, an-, ap-, at- as-, at-movement to, change into, addition or increaseadvance, adulterate, adjunct, ascend, affiliate, affirm, aggravate, alleviate, annotate, apprehend, arrive, assemble, attend
ante-before, precedingantecedent, ante-room
anti-also ant-opposing, against, the oppositeanti-aircraft, antibiotic, anticlimax, Antarctic
be-all over, all aroundbespatter, beset
completelybewitch, bemuse
having, covered withbejewelled
affect with (added to nouns)befog
cause to be (added to adjectives)becalm
com-also co-, col-, con-, cor-with, jointly, completelycombat, codriver, collude, confide, corrode
contra-against, oppositecontraceptive
counter-opposition, opposite directioncounter-attack, counteract
de-down, awaydescend, despair, depend, deduct
completelydenude, denigrate
removal, reversalde-ice, decamp
dia-also di-through, acrossdiagonal
dis-also di-negation, removal, expulsiondisadvantage, dismount, disbud, disbar
en-also em-put into or onengulf, enmesh
bring into the condition ofenlighten, embitter
intensificationentangle, enrage
ex-also e-, ef-outexit, exclude, expand
upwardexalt, extol
completelyexcruciate, exasperate
extra-outside, beyondextracurricular
hyper-beyond, more than, more than normalhypersonic, hyperactive
hypo-underhypodermic, hypothermia
in-also il-, im-not, withoutinfertile, inappropriate, impossible
also il-, im-, ir-in, into, towards, insideinfluence, influx, imbibe
infra-belowinfrared, infrastructure
inter-between, amonginteract, interchange
intra-inside, withinintramural, intravenous
non-absence, negationnon-smoker, non-alcoholic
ob-also oc-, of-, op-blocking, against, concealingobstruct, occult, offend, oppose
out-surpassing, exceedingoutperform
external, away fromoutbuilding, outboard
over-excessively, completelyoverconfident, overburdened, overjoyed
upper, outer, over, aboveovercoat, overcast
peri-round, aboutperimeter
post-after in time or orderpostpone
pre-before in time, place, order or importancepre-adolescent, prelude, precondition
pro-favouring, in support ofpro-African
acting forproconsul
motion forwards or awaypropulsion
before in time, place or orderprologue
re-againrepaint, reappraise, reawake
semi-half, partlysemicircle, semi-conscious
sub-also suc-, suf-, sug-, sup-, sur-, sus-at a lower positionsubmarine, subsoil
lower in ranksub-lieutenant
nearly, approximatelysub-tropical
syn-also sym-in union, acting togethersynchronize, symmetry
trans-across, beyondtransnational, transatlantic
into a different statetranslate
ultra-beyondultraviolet, ultrasonic
un-notunacceptable, unreal, unhappy, unmanned
reversal or cancellation of action or stateunplug, unmask
under-beneath, belowunderarm, undercarriage
lower in rankundersecretary
not enoughunderdeveloped