Aluminum Sulfate Definition

noun
A white crystalline compound, Al2 (SO4 )3 , used in papermaking, water purification, sanitation, and tanning.
American Heritage
A white crystalline salt, Al2(SO4)3, made by treating bauxite or clay with sulfuric acid: it is used in sizing paper, purifying water, fixing dyes, tanning, etc.
Webster's New World