from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Suffering from lunacy; insane.
- adj. Of or for the insane.
- adj. Wildly or giddily foolish: a lunatic decision.
- adj. Characterized by lunacy or eccentricity.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An insane person.
- adj. crazed, mad, insane, demented
from the GNU version of the Collaborative International Dictionary of English
- adj. Affected by lunacy; insane; mad; crazy; demented.
- adj. Of or pertaining to, or suitable for, an insane person; evincing lunacy
- n. A person affected by lunacy; an insane person, esp. one who has lucid intervals; a madman; a person of unsound mind.
from The Century Dictionary and Cyclopedia
- Moonstruck; affected by lunacy; periodically insane, with lucid intervals; crazy.
- Indicating lunacy; in the nature of lunacy.
- Of or like the moon.
- n. A person affected with lunacy; specifically, an insane person who has lucid intervals, or one whose unsoundness of mind is acquired, not congenital, as distinguished from an idiot.
- n. More generally (and in law), any person of unsound mind. See further under lunacy and insanity.
- n. Synonyms See insanity.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. insane and believed to be affected by the phases of the moon
- n. a reckless impetuous irresponsible person
- n. an insane person
Middle English lunatik, from Old French lunatique, from Latin lūnāticus, from lūna, moon; see leuk- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Old French lunatique, from Late Latin lunaticus ("moonstruck"), derived from Latin luna ("moon"). (Wiktionary)