/ Dictionary / Index A aggregation: Meaning and Definition of Find definitions for: ag•gre•ga•tion Pronunciation: (ag"ri-gā'shun), [key] — n. a group or mass of distinct or varied things, persons, etc.: an aggregation of complainants. collection into an unorganized whole. the state of being so collected. a group of organisms of the same or different species living closely together but less integrated than a society. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: aggregation (Thesaurus) aggregate aggregative Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language