Pronunciation: (al'um), [key]
1. Also called potash alum, potassium alum. a crystalline solid, aluminum potassium sulfate, K2SO4·Al2(SO4)3·24H2O, used in medicine as an astringent and styptic, in dyeing and tanning, and in many technical processes.
2. one of a class of double sulfates analogous to the potassium alum, as aluminum ammonium sulfate, having the general formula R2SO4·X2(SO4)3·24H2O, where R is a univalent alkali metal or ammonium, and X one of a number of trivalent metals.
3. (not in technical use) aluminum sulfate.
Pronunciation: (u-lum'), [key]
an alumna or alumnus.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.