1. An insane person
   "The homeless maniac muttered to himself as he wandered the streets";
   - lunatic, crazy [N. Amer, informal], loony [informal], looney [informal], nutcase [informal], headcase [informal]
    
2. A person who has an obsession with or excessive enthusiasm for something
   "He was a coffee maniac, trying every new blend he could find"

1. Wildly disordered
   "a maniac frenzy";
   - maniacal

Derived forms: maniacs

See also: insane

Type of: diseased person, enthusiast, fancier, sick person, sufferer

Encyclopedia: Maniac