maniac

[ mey-nee-ak ]
/ ˈmeɪ niˌæk /

noun

a raving or violently insane person; lunatic.
any intemperate or overly zealous or enthusiastic person: a maniac when it comes to details.

adjective

Origin of maniac

First recorded in 1595–1605, maniac is from the Medieval Latin word maniacus of, pertaining to madness. See mania, -ac

Example sentences from the Web for maniac

British Dictionary definitions for maniac

maniac
/ (ˈmeɪnɪˌæk) /

noun

a wild disorderly person
a person who has a great craving or enthusiasm for something a football maniac
psychiatry obsolete a person afflicted with mania

Word Origin for maniac

C17: from Late Latin maniacus belonging to madness, from Greek

Medical definitions for maniac

maniac
[ mānē-ăk′ ]

n.

An insane person.