- an insane person
- insane and believed to be affected by the phases of the moon
- daredevil: a reckless impetuous irresponsible person
- (lunacy) obsolete terms for legal insanity
- (lunacy) folly: foolish or senseless behavior
- A lunatic is a commonly used term for a person who is mentally ill, dangerous, foolish, unpredictable,: a condition once called lunacy.
- Lunatic is a French hip-hop duo consisting of Booba and Ali, both of whom have since gone onto successful solo careers.
- Lunatic is the fifth book in the Lost Books series, written by Ted DekKer. It occurs at the beginning of White, from Dekker's Circle Trilogy. It, along with the sixth book, Elyon, was released on June 2, 2009.
- (Lunacy (album)) Lunacy is an album released by Luna Sea on July 12, 2000. It was the band's last original studio album before disbanding in late 2000.
- (Lunacy (film)) Lunacy, also known as Šílení, is a 2005 film by Jan Švankmajer. The film is loosely based on two short stories, The System of Doctor Tarr and Professor Fether and The Premature Burial, by Edgar Allan Poe. It is also partly inspired by the works of the Marquis de Sade.
- (Lunacy (FIRST)) Lunacy is the game for the 2009 FIRST Robotics Competition. Announced on January 3, 2009, the name and some of the features of the game honor the 40th anniversary of the first manned mission to the Moon (Latin: Luna). It is FRC's 18th game. ...
- (Lunacy (videogame)) Lunacy is a videogame developed by System Sacom and published by Sega for Sega Saturn in 1997. Alternatively it was known as Torico in Europe, or, under its full title Gekka Mugentan Torico in Japan. ...
- (lunacy) The state of being mad, insanity a cyclical mental disease, apparently linked to the lunar phases insanity implying legal irresponsability; Something deeply misguided
- Jesus was not God, but he mistakenly believed that he was.