/ Dictionary / Index P presynaptic: Meaning and Definition of Find definitions for: pre•syn•ap•tic Pronunciation: (prē"si-nap'tik), [key] — adj. Physiol. being or occurring on the transmitting end of a discharge across a synapse. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. presurmise pret. Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language