insane

 
Pronunciation: /ɪnˈseɪn/

adjective

  • in a state of mind which prevents normal perception, behaviour, or social interaction; seriously mentally ill: he had gone insane
  • (of an action or quality) characterized or caused by madness: his eyes were glowing with insane fury
  • extremely annoyed: a fly whose buzzing had been driving me insane
  • extremely foolish; irrational: she had an insane desire to giggle

Derivatives

insanely

adverb

Origin:

mid 16th century: from Latin insanus, from in- 'not' + sanus 'healthy'