/ Dictionary / Index A addend: Meaning and Definition of Find definitions for: ad•dend Pronunciation: (ad'end, u-dend'), [key] — n. Math. any of a group of numbers or terms added together to form a sum. (formerly) a number that is added to another in forming a sum. Cf. augend. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: addend (Thesaurus) added-value tax addenda Related Content Daily Word Quiz: ounterfeit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language