/ Dictionary / Index P preexposure: Meaning and Definition of Find definitions for: pre•ex•po•sure Pronunciation: (prē"ik-spō'zhur), [key] — n. exposure beforehand. the exposing of a film to even light, before photographing a subject, to increase its sensitivity. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. preexist pref. Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language