WordNet (r) 3.0 (2006):

hypertext
    n 1: machine-readable text that is not sequential but is
         organized so that related items of information are
         connected; "Let me introduce the word hypertext to mean a
         body of written or pictorial material interconnected in
         such a complex way that it could not conveniently be
         presented or represented on paper"--Ted Nelson

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

hypertext
hypermedia

    A term coined by Ted Nelson around 1965 for a
   collection of documents (or "nodes") containing
   cross-references or "links" which, with the aid of an
   interactive browser program, allow the reader to move easily
   from one document to another.

   The extension of hypertext to include other media - sound,
   graphics, and video - has been termed "hypermedia", but
   is usually just called "hypertext", especially since the
   advent of the web and HTML.

   (2000-09-10)