(1):

(a.) Affected by lunacy; insane; mad.

(2):

(a.) Of or pertaining to, or suitable for, an insane person; evincing lunacy; as, lunatic gibberish; a lunatic asylum.

(3):

(n.) A person affected by lunacy; an insane person, esp. one who has lucid intervals; a madman; a person of unsound mind.