lunacy
noun /ˈluːnəsi/
/ˈluːnəsi/
[uncountable]- behaviour that is stupid or crazy synonym madness
- It's sheer lunacy driving in such weather.
- a comedy show full of inspired lunacy
- (old-fashioned) mental illness synonym madness
Word Originmid 16th cent. (originally referring to intermittent insanity believed to be caused by changes of the moon): from lunatic + -acy.