Alum
/ˈæl.əm/noun
A class of double salts, usually containing aluminum, used in dyeing, tanning, and as an astringent.
Did you know?The word ultimately comes from Greek and Latin names for a sharp, astringent mineral, and alums were so important in dyeing that controlling them could mean controlling color, trade, and status.
Etymological Timeline
Proto-Indo-European
PIE
*al-
“to grow, nourish; possibly also to be bitter/astringent in related formations”
Ancient Greek
Greek
ἄλας / ἄλμη
“salt; brine”
Late Latin
Latin
alumen
“alum, a strongly astringent mineral salt”
Old French
Old French
alum
“alum”
Middle English
English
alum
“alum, the mineral salt used in dyeing and medicine”
Modern English
English
alum
“a class of double salts used in industry and medicine”