/
ˈsɪərəm/
n.
(pl. sera
/-rə/
or serums)
- an amber-coloured, protein-rich liquid which separates out when blood coagulates.
- the blood serum of an animal, used to provide immunity to a pathogen or toxin by inoculation or as a diagnostic agent.
Etymology
C17: from L., lit. ‘whey’.