/ Dictionary / Index S subinterval: Meaning and Definition of Find definitions for: sub•in•ter•val Pronunciation: (sub-in'tur-vul), [key] — n. Math. an interval that is a subset of a given interval. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. subinfluent subirrigate Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language