The Collaborative International Dictionary of English v.0.48:

Isomorphic \I`so*mor"phic\, a.
   1. Isomorphous.
      [1913 Webster]

   2. (Biol.) Alike in form; exhibiting isomorphism.
      [Webster 1913 Suppl.]

   3. Of or pertaining to sets related by an isomorphism.
      [PJC]

WordNet (r) 3.0 (2006):

isomorphic
    adj 1: having similar appearance but genetically different [syn:
           isomorphous, isomorphic]

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

isomorphic

    Two mathematical objects are isomorphic if they
   have the same structure, i.e. if there is an isomorphism
   between them.  For every component of one there is a
   corresponding component of the other.

   (1995-03-25)