/ Dictionary / Index A aluminum ammonium sulfate: Meaning and Definition of Find definitions for: alu'minum ammo'nium sul'fate Pronunciation: [key] — Chem. Chem. a crystalline solid, AlNH(SO)&multiplydot;12HO, used chiefly as a size in the manufacture of paper; alum. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. aluminum acetate aluminum borate Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language