Casein
/ˈkeɪ.si.ɪn/noun
The main protein in milk, especially important in cheese-making.
Did you know?Casein was named from Latin *caseus* “cheese,” because it is the protein that clots and becomes the basis of cheese—an everyday word with a very literal dairy origin.
Etymological Timeline
Proto-Indo-European
PIE
*kwat-
“to ferment, curdle, or become sour”
Latin
Latin
caseus
“cheese”
Late Latin
Latin
caseīna
“of cheese; cheesy substance”
17th–18th Century
French/English
caséine / casein
“the chief protein substance of milk, first isolated from cheese-like curds”
Modern English
English
casein
“the principal protein found in milk and used in foods, adhesives, and plastics”