serum
/ˈsɪərəm; `sɪrəm/ n
(pl sera / ˈsɪərə; `sɪrə/ or ~ s) (medical 医)
1 [U]
(a) watery liquid in animal bodies （动物体内的）浆液.
(b) thin yellowish liquid that remains from blood after it has clotted 血清.
2 [C, U] (dose of) such liquid taken from an animal that is immune to a disease, used for inoculations （一剂）免疫血清（用於接种或预防注射）. Cf 参看 vaccine.