[ɪnˈseɪn], (Adjective)

Definitions:
- very foolish, irrational, or strange
(e.g: everything about the business seems insane)

- lacking the ability to think and behave in ways considered to be normal, especially on account of serious mental illness (not in current technical use)
(e.g: he had gone insane)

- shocking; outrageous
(e.g: they were making insane amounts of money)


Phrases:

Origin:
mid 16th century: from Latin insanus, from in- ‘not’ + sanus ‘healthy’