albumin (albumen) Type of water-soluble protein occurring in animal tissues and fluids. Principal forms are egg albumin (egg white), milk albumin and blood albumin. In a healthy human, it constitutes about 5% of the body's total weight. It is composed of a colourless, transparent fluid called plasma in which are suspended microscopic erythrocytes (red blood cells), leucocytes (white blood cells) and platelets.

albumin (albumen) A group of relatively small proteins which are soluble in water and readily coagulated by heat. Ovalbumin is the main protein of egg‐white, lactalbumin occurs in milk, and plasma or serum albumin is one of the major blood proteins. Serum albumin concentration is sometimes measured as an index of protein‐energy malnutrition.

Often used as a non‐specific term for proteins (e.g. albuminuria is the excretion of proteins in the urine).

albumin (albumen) A water-soluble, globular, simple protein that occurs in a variety of tissue fluids, including plasma, synovial fluid, tears, egg white, lymph, and cerebro-spinal fluid. Its functions appear to be primarily those of osmoregulation and the transport of materials.

albumin One of a group of globular proteins that are soluble in water but form insoluble coagulates when heated. Albumins occur in egg white (the protein component of which is known as albumen), blood, milk, and plants. Serum albumins, which constitute about 55% of blood plasma protein, help regulate the osmotic pressure and hence plasma volume. They also bind and transport fatty acids. α-lactalbumin is one of the proteins in milk.

al·bu·min / alˈbyoōmən/ • n. Biochem. a simple form of protein that is soluble in water and coagulable by heat, such as that found in egg white, milk, and (in particular) blood serum.