D defs.my
Entry 4 senses Webster, 1913

Insane

/ĭnˌ-sān'/ · In·sane · IPA /ɪnˈseɪn/
01 a. Exhibiting unsoundness or disorder of mind; not sane; mad; deranged in mind; delirious; distracted. See Insanity, 2.
  1. 1.
    Exhibiting unsoundness or disorder of mind; not sane; mad; deranged in mind; delirious; distracted. See Insanity, 2. See: Insanity
  2. 2.
    Used by, or appropriated to, insane persons; as, an insane hospital.
  3. 3.
    Causing insanity or madness.[R.]
    “Or have we eaten on the insaneroot That takes the reason prisoner ?” Shak.
  4. 4.
    Characterized by insanity or the utmost folly; chimerical; unpractical; as, an insane plan, attempt, etc.
    “I know not which was the insane measure.” Southey.