US usually tranquilize, [UK and ANZ] usually -ise [verb] [T]To tranquillize an animal or person is to give them a drug that makes them become unconscious or calm.The leopard died when zoo officials tried to tranquillize it.Sales of tranquillizing medicines began to drop as doctors became more aware of the risks associated with them.
TRANQUILLIZE
Meaning of TRANQUILLIZE in English
Cambridge English vocab. Кембриджский английский словарь. 2012