|any of various disorders in which a person's thoughts, emotions, or behaviour are so abnormal as to cause suffering to himself, herself, or other people|
mental illness n.
Any of various disorders characterized chiefly by abnormal behavior or an inability to function socially, including diseases of the mind and personality and certain diseases of the brain. Also called mental disease, mental disorder.
|mental illness (měn'tl) Pronunciation Key
Any of various psychiatric disorders or diseases, usually characterized by impairment of thought, mood, or behavior.