n.
Pronunciation: ' a-l ə m
Function: noun
Etymology: Middle English, from Anglo-French alum, alun, from Latin alumen
Date: 14th century
1 : a potassium aluminum sulfate KAl(SO 4 ) 2 ·12H 2 O or an ammonium aluminum sulfate NH 4 Al(SO 4 ) 2 ·12H 2 O used especially as an emetic and as an astringent and styptic
2 : any of various double salts isomorphous with potassium aluminum sulfate
3 : ALUMINUM SULFATE