/ Dictionary / Index P proterotype: Meaning and Definition of Find definitions for: prot•er•o•type Pronunciation: (prot'ur-u-tīp", prō'tur-), [key] — n. a primary type. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. protero- Proterozoic Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language