serum
serum /ˈsɪə.rəm/ aep /ˈsɪr.əm/ noun [C or U] (PLURAL sera /ˈsɪə.rə/ aep/ˈsɪr.ə/ or serums)
1 F0 the part of the blood that has no colour, or this liquid taken from an animal and put into a human in order to fight an infection: » cholesterol levels in blood serum» an anti-venom serumThesaurus+: ↑The circulatory system and blood2 F0 a substance in beauty products that is designed to improve your hair or skin and make it less dry Thesaurus+: ↑Beauty treatments |