[ɪnˈsanɪti], (Noun)

Definitions:
- extreme foolishness or irrationality
(e.g: it might be pure insanity to take this loan)

- inability to think and behave in ways considered to be normal and rational, especially on account of serious mental illness (not in current technical use)
(e.g: he suffered from bouts of insanity)


Phrases:

Origin:
late 16th century: from Latin insanitas, from insanus (see insane)