The Collaborative International Dictionary of English v.0.48:

Intermedium \In`ter*me"di*um\, n.; pl. Intermediums, L.
   Intermedia. [NL., neut. of L. intermedius intermediate.]
   [1913 Webster]
   1. Intermediate space. [R.]
      [1913 Webster]

   2. An intervening agent or instrument. --Cowper.
      [1913 Webster]

   3. (Anat.) The bone or cartilage between the radiale and
      ulnare in the carpus, and between the tibiale and fibulare
      in the tarsus. It corresponds to the lunar in the carpus,
      and to a part of the astragalus in the tarsus of man and
      most mammals.
      [1913 Webster]

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

Intermedia

    A hypertext system developed by a research group at
   IRIS (Brown University) to support education and research.
   Intermedia was a "shell" over A/UX 1.1, programmed using an
   object-oriented toolkit and standard DBMS functions.  The
   data model and architecture were designed for flexibility and
   consistency.

   Intermedia consisted of several applications sharing an
   event-driven gui.  These included a text editor (InterText),
   graphics editor (InterDraw), picture viewer (InterPix), timeline
   editor (InterVal), 3D model viewer (InterSpect), animation
   editor (InterPlay) and video editor (InterVideo).

   [Yankelovich et al, "Intermedia: The Concept and the Construction
   of a Seamless Information Environment"

(http://research.microsoft.com/en-us/um/people/sdrucker/papers/intermedia1.pdf)]

   (http://elab.eserver.org/hfl0032.html).

   (2014-11-02)