/ Dictionary / Index N number theory: Meaning and Definition of Find definitions for: num'ber the"ory Pronunciation: [key] — Math. Math. the study of integers and their relation to one another. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. numbers pool number three iron Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language