Lū'na-cy, n.

n. [Lat. lunaticus. See LUNATIC.] A species of 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; madness; insanity, or any unsoundness of mind. Brande. Burrill. New. Am. Cyc.

Synonyms—Insanity; derangement; craziness; mania. See INSANITY.