lunacy

lunacy is a   Noun

Definition:

[1] Insanity or madness; properly, the kind of insanity which is broken by intervals of reason, -- formerly supposed to be influenced by the changes of the moon; any form of unsoundness of mind, except idiocy; mental derangement or alienation. Brande. Burrill. Your kindred shuns your house As beaten hence by your strange lunacy. Shak.

[2] A morbid suspension of good sense or judgment, as through fanaticism. Dr. H. More.

Synonyms: