n. 1 narcotic, tranquillizer, opiate, sleeping-pill, soporific, calmative, anodyne, depressant, hypnotic, barbiturate, lenitive, Colloq downer, knock-out drop, Slang Mickey (Finn) The doctor has given him a sedative and he should sleep now
adj. 2 narcotic, tranquillizing, relaxing, soothing, calming, allaying, opiate, soporific, sleep-inducing, calmative, anodyne, lenitive, depressing, hypnotic I found that listening to a recording of surf splashing on a beach has a sedative effect