/ Dictionary / Index A activated alumina: Meaning and Definition of Find definitions for: ac'tivated alu'mina Pronunciation: [key] — Chem. Chem. alumina in the form of granules having many fine pores, used to adsorb water and various gases. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. activate activated carbon Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language