/ Dictionary / Index P prost: Meaning and Definition of Find definitions for: prost Pronunciation: (prōst), [key] — interj. prosit. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Prosser prostacyclin Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language