(~s)
1.
A ~ is a liquid that is injected into someone’s blood to protect them against a poison or disease.
N-VAR
2.
Serum is the watery, pale yellow part of blood.
N-UNCOUNT
(~s)
1.
A ~ is a liquid that is injected into someone’s blood to protect them against a poison or disease.
N-VAR
2.
Serum is the watery, pale yellow part of blood.
N-UNCOUNT
Collins COBUILD. Толковый словарь английского языка для изучающих язык Коллинз COBUILD (международная база данных языков Бирмингемского университета) . 2012