Source : WordNet®

acronym
     n : a word formed from the initial letters of a multi-word name

Source : Free On-Line Dictionary of Computing

acronym
     
         An identifier formed from some of the letters (often
        the initials) of a phrase and used as an abbreviation.  {This
        dictionary} contains a great many acronyms; see the contents
        page for a list.
     
        See also {TLA}.
     
        (1995-03-15)