Main Entry:

¹se·rum

Pronunciation:

\ˈsir-əm\

Function:

noun

Inflected Form(s):

plural serums or se·ra \-ə\

Etymology:

Latin, whey, wheylike fluid; akin to Greek oros whey

Date:

1665

1: the watery portion of an animal fluid remaining after coagulation: a (1): blood serum (2): antiserum b: whey c: a normal or pathological serous fluid (as in a blister) 2: the watery part of a plant fluid