Dictionary
al•um
Pronunciation: (al'um), [key]—
n. Chem.
1. Also called
potash alum, potassium alum. a crystalline solid, aluminum potassium sulfate, K
2SO
4·Al
2(SO
4)
3·24H
2O, 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 R
2SO
4·X
2(SO
4)
3·24H
2O, 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.
a•lum
Pronunciation: (u-lum'), [key]—
n. Informal.
an alumna or alumnus.
alum.
Chem.
aluminum.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.