a drug that is taken for nonmedicinal reasons (usually for mind-altering effects); drug abuse can lead to physical and mental damage and (with some substances) dependence and addiction

(medicine) something that treats or prevents or alleviates the symptoms of disease

capable of depressing physiological or psychological activity or response by a chemical agent

lower someone's spirits; make downhearted

a colorless crystalline drug used as a sedative; irritates the stomach and can be addictive

sedative (trade name Doriden) used to treat some sleep disorders

a sedative that depresses activity of the central nervous system and reduces anxiety and induces sleep