WordNet (r) 3.0 (2006):

intensional
    adj 1: used of the set of attributes that distinguish the
           referents of a given word

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

intensional

    A description of properties, e.g. intensional
   equality, that relate to how an object is implemented as
   opposed to extensional properties which concern only how its
   output depends on its input.

   (1995-01-12)