The Collaborative International Dictionary of English v.0.48:

GIF \GIF\, n. [Acronym from Graphics Interchange Format.]
   (Computers)
   1. The Graphics Interchange Format, one of the most popular
      standardized formats for storing graphic data in binary
      computer files. The standard has been revised several
      times, and includes provisions for interlacing and
      animating images. Its disadvantage is that it can store
      only 256 colors. Compare JPEG.
      [PJC]

   2. (Computers) An image stored in GIF[1] format, or the file
      in which the image is stored; as, he sent three GIF's with
      lovely pictures of his children.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Gif \Gif\, conj. [AS. See If.]
   If. [Obs.]
   [1913 Webster]

   Note: Gif is the old form of if, and frequently occurs in the
         earlier English writers. See If.
         [1913 Webster]

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

Graphics Interchange Format
GIF
GIF89

    /gif/, occasionally /jif/ (GIF, GIF
   89A) A standard for digitised images compressed with the
   LZW algorithm, defined in 1987 by CompuServe (CIS).

   Graphics Interchange Format and GIF are service marks of
   CompuServe Incorporated.  This only affects use of GIF
   within Compuserve, and pass-through licensing for software to
   access them, it doesn't affect anyone else's use of GIF.  It
   followed from a 1994 legal action by Unisys against CIS for
   violating Unisys's LZW software patent.  The CompuServe
   Vice President has stated that "CompuServe is committed to
   keeping the GIF 89A specification as an open, fully-supported,
   non-proprietary specification for the entire on-line community
   including the web".

   Filename extension: .gif.

   File format (ftp://peipa.essex.ac.uk/ipa/info/file-formats).

   GIF89a specification
   (http://asterix.seas.upenn.edu/~mayer/lzw_gif/gif89a.html).

   See also progressive coding, animated GIF.

   (2000-09-12)