The definition of a lunatic is a person who is either actually crazy or who is acting crazy and wild in his behavior.(noun)
Lunatic is defined as someone or something that is wild, crazy or absurd.(adjective)
Wild and crazy behavior is an example of something that would be described as lunatic behavior.
See lunatic in Webster's New World College Dictionary
Origin: ME lunatik < OFr lunatique < LL lunaticus, moon-struck, crazy < L luna, the moon: see light
See lunatic in American Heritage Dictionary 4
Origin: Middle English lunatik
Origin: , from Old French lunatique
Origin: , from Latin lūnāticus
Origin: , from lūna, moon; see leuk- in Indo-European roots.
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