from
The Collaborative International Dictionary of English v.0.48
Serum \Se"rum\ (s[=e]"r[u^]m), n. [L., akin to Gr. ???, Skr.
s[=a]ra curd.] (Physiol.)
(a) The watery portion of certain animal fluids, as blood,
milk, etc.
(b) A thin watery fluid, containing more or less albumin,
secreted by the serous membranes of the body, such as the
pericardium and peritoneum.
[1913 Webster]
{Blood serum}, the pale yellowish fluid which exudes from the
clot formed in the coagulation of the blood; the liquid
portion of the blood, after removal of the blood
corpuscles and the fibrin.
{Muscle serum}, the thin watery fluid which separates from
the muscles after coagulation of the muscle plasma; the
watery portion of the plasma. See {Muscle plasma}, under
{Plasma}.
{Serum albumin} (Physiol. Chem.), an albuminous body, closely
related to egg albumin, present in nearly all serous
fluids; esp., the albumin of blood serum.
{Serum globulin} (Physiol. Chem.), paraglobulin.
{Serum of milk} (Physiol. Chem.), the whey, or fluid portion
of milk, remaining after removal of the casein and fat.
[1913 Webster]