Common Prefixes in English

Prefix

Meaning

Example

a-, an-

without

amoral

ante-

before

antecedent

anti-

against

anticlimax

auto-

self

autopilot

circum-

around

circumvent

co-

with

copilot

com-, con-

with

companion, contact

contra-

against

contradict

de-

off, away from

devalue

dis-

not

disappear

en-

put into

enclose

ex-

out of, former

extract, ex-president

extra-

beyond, more than

extracurricular

hetero-

different

heterosexual

homo-

same

homonym

hyper-

over, more

hyperactive

il-, im-, in-, ir-

not, without

illegal, immoral, inconsiderate, irresponsible

in-

into

insert

inter-

between

intersect

intra-

between

intravenous

macro-

large

macroeconomics

micro-

small

microscope

mono-

one

monocle

non-

not, without

nonentity

omni-

all, every

omniscient

post-

after

postmortem

pre-, pro-

before, forward

precede, project

sub-

under

submarine

syn-

same time

synchronize

trans-

across

transmit

tri-

three

tricycle

un-

not

unfinished

uni-

one

unico