SEDATIVE Meaning of SEDATIVE in English ■ adjective promoting calm or inducing sleep. ■ noun a ~ drug.OriginME: from OFr. sedatif or med. L. sedativus , from L. sedat- , sedare (see sedate 1 ). Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004