The Collaborative International Dictionary of English v.0.48:

Maniac \Ma"ni*ac\, a. [F. maniaque. See Mania.]
   Raving with madness; raging with disordered intellect;
   affected with mania; mad.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

maniac \ma"ni*ac\, n.
   A raving lunatic; a madman.
   [1913 Webster]

WordNet (r) 3.0 (2006):

maniac
    adj 1: wildly disordered; "a maniacal frenzy" [syn: maniacal,
           maniac(p)]
    n 1: an insane person [syn: lunatic, madman, maniac]
    2: a person who has an obsession with or excessive enthusiasm
       for something

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "maniac":
   aliene, batty, bedlamite, berserk, borderline case, crackbrain,
   cracked, crackpot, crazed, crazy, delirious, dement, demented,
   demoniac, deranged, energumen, enthusiast, fan, fanatic, fiend,
   flake, fou, frantic, freak, frenetic, frenzied, furious, idiot,
   kook, loon, loony, lunatic, mad, madman, meshuggenah, non compos,
   noncompos, nut, phrenetic, psychopath, psychotic, rabid, raging,
   ranting, raving lunatic, screwball, unsound, violent, weirdo, wild,
   zealot



The Free On-line Dictionary of Computing (30 December 2018):

Mathematical Analyzer, Numerical Integrator and Computer
MANIAC

    (MANIAC, Or "Mathematical Analyzer, Numerator,
   Integrator, and Computer") An early computer, built for the Los
   Alamos Scientific Laboratory.  MANIAC began operation in March
   1952.  Typical of early computers, it ran its own propriatery
   language.  It was succeeded by MANIAC II in 1957.  A MANIAC
   III was built at the University of Chicago in 1964.

   Contrary to legend, MANIAC did not run MAD (Michigan Algorithm
   Decoder), which was not invented until 1959.

   (2013-05-05)