/ Dictionary / Index P preatomic: Meaning and Definition of Find definitions for: pre•a•tom•ic Pronunciation: (prē"u-tom'ik), [key] — adj. of or pertaining to the period of history preceding the atomic age. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. preaseptic preaudit Related Content Daily Word Quiz: effervescent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language