[ key-seen, -see-in, key-seen ]
/ ˈkeɪ sin, -si ɪn, keɪˈsin /


Biochemistry. a protein precipitated from milk, as by rennet, and forming the basis of cheese and certain plastics.
Fine Arts.
  1. an emulsion made from a solution of this precipitated protein, water, and ammonia carbonate.
  2. a paint in which this emulsion is used as a binder.
  3. a picture produced with this paint and emulsion.



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Origin of casein

1835–45; <Latin cāse(us) cheese1 + -in2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

Example sentences from the Web for casein

British Dictionary definitions for casein

/ (ˈkeɪsɪɪn, -siːn) /


a phosphoprotein, precipitated from milk by the action of rennin, forming the basis of cheese: used in the manufacture of plastics and adhesivesAlso called (US): paracasein

Word Origin for casein

C19: from Latin cāseus cheese + -in
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for casein

[ kāsēn′, -sē-ĭn ]


A white, tasteless, odorless protein precipitated from cow's milk by rennin that is the basis of cheese and is used to make plastics, adhesives, paints, and foods.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for casein

[ kāsēn′, -sē-ĭn ]

A white, tasteless, odorless mixture of related phosphoproteins precipitated from milk by rennin. Casein is very nutritious, as it contains all of the essential amino acids as well as all of the common nonessential ones. It is the basis of cheese and is used to make plastics, adhesives, paints, and foods.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.