/ Dictionary / Index P proper fraction: Meaning and Definition of Find definitions for: prop'er frac'tion Pronunciation: [key] — Math. Math. a fraction having the numerator less, or lower in degree, than the denominator. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. proper adjective proper function 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