Bible Dictionary
Lunatic
A lunatic was a person described as suffering from a condition resembling epilepsy, sometimes accompanied by demonic possession. The term reflects the ancient association of such symptoms with the moon.
Definition
A lunatic was a person regarded as suffering from symptoms probably resembling epilepsy. The term reflected the belief that such symptoms became more severe as the moon increased. In the biblical accounts, the condition could be distinguished from demonic possession, although the designation was also applied to a person declared to be possessed.
Biblical Usage
“Lunatics” are distinguished from demoniacs in Matthew 4:24. In Matthew 17:15, the designation is applied to a person who is declared to have been possessed. Thus the biblical usage does not treat every such condition as evidence of possession.
Historical Background
The term comes from the Latin word for moon. Ancient belief connected the symptoms with changes in the moon, especially its increase.
Scripture References
Historical Bible Dictionaries
Easton's Bible Dictionary
Probably the same as epileptic, the symptoms of which disease were supposed to be more aggravated as the moon increased. In Matt. 4:24 “lunatics” are distinguished from demoniacs. In 17:15 the name “lunatic” is applied to one who is declared to have been possessed. (See DAEMONIAC.)