/ Dictionary / Index S sign of aggregation: Meaning and Definition of Find definitions for: sign' of aggrega'tion Pronunciation: [key] — Math. Math. any of the signs used to indicate grouping in an algebraic expression: vinculum, bar, or raised horizontal line, &aspplusspbhorbarover;; a pair of parentheses, (a + b); a pair of brackets, Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sign manual sign-off Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language