alum
//ˈæl.əm//
Noun
alumSingular
alumsPlural
1
A chemical compound, typically potassium aluminum sulfate, used in dyeing, tanning, and as an astringent.
Alum is commonly used as a mordant in fabric dyeing.
Noun
alumSingular
alumsPlural
1
A graduate or former student of a particular school, college, or university.
She is a proud alum of Harvard University.