n.
Pronunciation: ' sir- ə m
Function: noun
Inflected Form: 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