PREFIXES

PREFIXES

A 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.

A prefix goes at the beginning of a word. A suffix goes at the end of a word.

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.

prefix		meaning	examples
a-	also an-	not, without	atheist, anaemic
a-		to, towards	aside, aback
		in the process of, in a particular state	a-hunting, aglow
a-		of	anew
		completely	abashed
ab-	also abs-	away, from	abdicate, abstract
ad-	also a-, ac-, af-, ag- al-, an-, ap-, at- as-, at-	movement to, change into, addition or increase	advance, adulterate, adjunct, ascend, affiliate, affirm, aggravate, alleviate, annotate, apprehend, arrive, assemble, attend
ante-		before, preceding	antecedent, ante-room
anti-	also ant-	opposing, against, the opposite	anti-aircraft, antibiotic, anticlimax, Antarctic
be-		all over, all around	bespatter, beset
		completely	bewitch, bemuse
		having, covered with	bejewelled
		affect with (added to nouns)	befog
		cause to be (added to adjectives)	becalm
com-	also co-, col-, con-, cor-	with, jointly, completely	combat, codriver, collude, confide, corrode
contra-		against, opposite	contraceptive
counter-		opposition, opposite direction	counter-attack, counteract
de-		down, away	descend, despair, depend, deduct
		completely	denude, denigrate
		removal, reversal	de-ice, decamp
dia-	also di-	through, across	diagonal
dis-	also di-	negation, removal, expulsion	disadvantage, dismount, disbud, disbar
en-	also em-	put into or on	engulf, enmesh
		bring into the condition of	enlighten, embitter
		intensification	entangle, enrage
ex-	also e-, ef-	out	exit, exclude, expand
		upward	exalt, extol
		completely	excruciate, exasperate
		previous	ex-wife
extra-		outside, beyond	extracurricular
hemi-		half	hemisphere
hyper-		beyond, more than, more than normal	hypersonic, hyperactive
hypo-		under	hypodermic, hypothermia
in-	also il-, im-	not, without	infertile, inappropriate, impossible
	also il-, im-, ir-	in, into, towards, inside	influence, influx, imbibe
infra-		below	infrared, infrastructure
inter-		between, among	interact, interchange
intra-		inside, within	intramural, intravenous
non-		absence, negation	non-smoker, non-alcoholic
ob-	also oc-, of-, op-	blocking, against, concealing	obstruct, occult, offend, oppose
out-		surpassing, exceeding	outperform
		external, away from	outbuilding, outboard
over-		excessively, completely	overconfident, overburdened, overjoyed
		upper, outer, over, above	overcoat, overcast
peri-		round, about	perimeter
post-		after in time or order	postpone
pre-		before in time, place, order or importance	pre-adolescent, prelude, precondition
pro-		favouring, in support of	pro-African
		acting for	proconsul
		motion forwards or away	propulsion
		before in time, place or order	prologue
re-		again	repaint, reappraise, reawake
semi-		half, partly	semicircle, semi-conscious
sub-	also suc-, suf-, sug-, sup-, sur-, sus-	at a lower position	submarine, subsoil
		lower in rank	sub-lieutenant
		nearly, approximately	sub-tropical
syn-	also sym-	in union, acting together	synchronize, symmetry
trans-		across, beyond	transnational, transatlantic
		into a different state	translate
ultra-		beyond	ultraviolet, ultrasonic
		extreme	ultramicroscopic
un-		not	unacceptable, unreal, unhappy, unmanned
		reversal or cancellation of action or state	unplug, unmask
under-		beneath, below	underarm, undercarriage
		lower in rank	undersecretary
		not enough	underdeveloped