n. (pl. -ies) 1 insanity (orig. of the intermittent kind attributed to changes of the moon); the state of being a lunatic. 2 Law such mental unsoundness as interferes with civil rights or transactions. 3 great folly or eccentricity; a foolish act.
LUNACY
Meaning of LUNACY in English
Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012