Pronunciation: (lOO'nu-tik),[key] —n. 1. an insane person.
2. a person whose actions and manner are marked by extreme eccentricity or recklessness.
3. Law.a person legally declared to be of unsound mind and who therefore is not held capable or responsible before the law.
—adj. 1. insane; demented; crazy.
2. characteristic or suggestive of lunacy; wildly or recklessly foolish.
3. designated for or used by the insane: a lunatic asylum. 4. gaily or lightheartedly mad, frivolous, eccentric, etc.: She has a lunatic charm that is quite engaging.Also,lu•nat•i•calPronunciation: (lOO-nat'i-kul)[key](for defs. 4, 5, 7).