/ Dictionary / Index S summate: Meaning and Definition of Find definitions for: sum•mate Pronunciation: (sum'āt), [key] — -mat•ed, -mat•ing. to add together; total; sum up. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: summate (Thesaurus) summary proceeding Summa Theologica* Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language