Definition of insanity:
foolishness, folly, insaneness, aberration, psychopathy, unbalance, disease, brainsickness, foolhardiness, sane, idiocy, stupidity, nonsense, foolery, monomania, ability, senselessness, absurdity, alienation, tomfoolery, silliness, imbecility, zaniness, disturbance, mental illness, complex, phobia, preposterousness.
disorder (part of speech: noun)
- insanity (part of speech: noun)
- "The Pacha of Many Tales", Captain Frederick Marryat.
- "Orthodoxy", G. K. Chesterton.
- "In the Heart of a Fool", William Allen White.