/ Dictionary / Index Q quintile: Meaning and Definition of Find definitions for: quin•tile Pronunciation: (kwin'til, -tīl), [key] — n. a quantile for the special case of five equal proportions. a quintile aspect. —adj. of or pertaining to the aspect of two heavenly bodies that are one fifth of the zodiac, or 72°, apart. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. quintic Quintilian Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language