/ Dictionary / Index P protolog: Meaning and Definition of Find definitions for: pro•to•log Pronunciation: (prōt'l-ôg", -og"), [key] — n. Biol. the original description of a species, genus, etc. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. protolithic protomartyr Related Content Daily Word Quiz: boorish Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language