The Collaborative International Dictionary of English v.0.48:

Demigod \Dem"i*god\, n.
   A half god, or an inferior deity; a fabulous hero, the
   offspring of a deity and a mortal.
   [1913 Webster]

WordNet (r) 3.0 (2006):

demigod
    n 1: a person with great powers and abilities [syn: demigod,
         superman, Ubermensch]
    2: a person who is part mortal and part god [syn: daemon,
       demigod]

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "demigod":
   Achilles, David, Hector, Roland, Samson, a man, brave, bulldog,
   chutzpanik, decorated hero, demigoddess, fighting cock, gallant,
   gamecock, god, goddess, godkin, godlet, godling, good soldier,
   hero, heroine, idol, lion, man of courage, paladin, phoenix,
   stalwart, superhuman, the brave, tiger, valiant, valiant knight



The Jargon File (version 4.4.7, 29 Dec 2003):

demigod
 n.

    A hacker with years of experience, a world-wide reputation, and a major
    role in the development of at least one design, tool, or game used by or
    known to more than half of the hacker community. To qualify as a genuine
    demigod, the person must recognizably identify with the hacker community
    and have helped shape it. Major demigods include Ken Thompson and Dennis
    Ritchie (co-inventors of Unix and C), Richard M. Stallman (inventor of
    EMACS), Larry Wall (inventor of Perl), Linus Torvalds (inventor of 
    Linux), and most recently James Gosling (inventor of Java, NeWS, and 
    GOSMACS) and Guido van Rossum (inventor of Python). In their hearts of
    hearts, most hackers dream of someday becoming demigods themselves, and
    more than one major software project has been driven to completion by the
    author's veiled hopes of apotheosis. See also net.god, true-hacker, 
    ubergeek. Since 1995 or so this term has been gradually displaced by 
    ubergeek.


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

demigod

    A hacker with years of experience, a national
   reputation, and a major role in the development of at least
   one design, tool, or game used by or known to more than half
   of the hacker community.  To qualify as a genuine demigod, the
   person must recognisably identify with the hacker community
   and have helped shape it.  Major demigods include Ken
   Thompson and Dennis Ritchie (co-inventors of Unix and
   C) and Richard Stallman (inventor of Emacs).  In their
   hearts of hearts, most hackers dream of someday becoming
   demigods themselves, and more than one major software project
   has been driven to completion by the author's veiled hopes of
   apotheosis.

   See also net.god, true-hacker.

   [Jargon File]

   (1994-10-27)