adj. & n.
adj. 1 of or in the mind. 2 done by the mind. 3 colloq. a insane. b crazy, wild, eccentric (is mental about pop music).
n. colloq. a mental patient. mental age the degree of a person's mental development expressed as an age at which the same degree is attained by an average person. mental arithmetic arithmetic performed in the mind. mental asylum (or home or hospital or institution) an establishment for the care of mental patients. mental cruelty the infliction of suffering on another's mind, esp. Law as grounds for divorce. mental defective esp. US a person with impaired mental abilities. mental deficiency imperfect mental development leading to abnormally low intelligence. mental illness a disorder of the mind. mental nurse a nurse dealing with mentally ill patients. mental patient a sufferer from mental illness. mental reservation a qualification tacitly added in making a statement etc. mentally adv.
[ ME f. OF mental or LL mentalis f. L mens -ntis mind ]