/kay"seen, -see in, kay seen"/ , n.
1. Biochem. a protein precipitated from milk, as by rennet, and forming the basis of cheese and certain plastics.
2. Fine Arts.
a. an emulsion made from a solution of this precipitated protein, water, and ammonia carbonate.
b. a paint in which this emulsion is used as a binder.
c. a picture produced with this paint and emulsion.
[ 1835-45; case ( us ) CHEESE + -IN 2 ]