/ Dictionary / Index P proper adjective: Meaning and Definition of Find definitions for: prop'er ad'jective Pronunciation: [key] — Gram. Gram. an adjective formed from a proper noun, as American from America. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. proper proper fraction 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