lunacy

lu·na·cy

(lū'nă-sē), This imprecise and outmoded word is best avoided in medical speech and writing.

1. An obsolete term for a form of insanity characterized by alternating lucid and insane periods, believed to be influenced by phases of the moon.

2. Any form of insanity.

3. Insanity as defined variously by law.

[L. luna, moon]

Farlex Partner Medical Dictionary © Farlex 2012

lunacy

A legal term for psychotic disorder, no longer used by doctors. The origins of the word derive from the old belief that madness was caused by the full moon. From the Latin luna , the moon.

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005