se‧rum /ˈsɪərəm $ ˈsɪr-/ noun (plural serums or sera /-rə/) [uncountable and countable]
[Date: 1600-1700; Language: Latin]

1. medical a liquid containing substances that fight infection or poison, that is put into a sick person’s blood ⇒ vaccine

2. technical the thin part of blood or the liquid from a plant

[TahlilGaran] Dictionary of Contemporary English ▲