Main Entry: ¹se·rum

Pronunciation: \ˈsir-əm\

Function: noun

Inflected Form(s): plural se·ra \-ə\ or serums

: the watery portion of an animal fluid remaining after coagulation: a (1) : the clear yellowish fluid that remains from blood plasma after fibrinogen, prothrombin, and other clotting factors have been removed by clot formation—called also blood serum (2) : antiserum b : a normal or pathological serous fluid (as in a blister)