ALUM

I. noun Etymology: Middle English, from Anglo-French ~, alun, from Latin ~en Date: 14th century a potassium ~inum sulfate KAl(SO 4 ) 2 12H 2 O or an ammonium ~inum sulfate NH 4 Al(SO 4 ) 2 12H 2 O used especially as an emetic and as an astringent and styptic, any of various double salts isomorphous with potassium ~inum sulfate, ~inum sulfate , II. noun Etymology: by shortening Date: 1930 ~nus , ~na , III. abbreviation ~inum