mental illness is a noun meaning "any disease of the mind; the psychological state of someone who has emotional or behavioral problems serious enough to require psychiatric intervention". It carries one recorded sense.
any disease of the mind; the psychological state of someone who has emotional or behavioral problems serious enough to require psychiatric intervention
Definitions, synonyms and semantic relations for mental illness come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.