Pre- (meaning before)

preview

(n.) something seen in advance; (v.) to view beforehand

prefix

A syllable or word that comes before a root word to change its meaning

pretest

A test before the real test, usually given to see what is already known.

precaution

a measure taken in advance to prevent harm

preapprove

to authorize or give permission in advance

precede

to come before something else in time, order, or rank

prejudge

to make a decision before you have all of the facts

prepay

to pay for something before it needs to be paid in full

predict

to say what will happen before it occurs

prevent

to stop something before it happens