WordNet (r) 3.0 (2006):

instantiation
    n 1: a representation of an idea in the form of an instance of
         it; "how many instantiations were found?"

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

instantiation
instantiate

    Producing a more defined version of some object
   by replacing variables with values (or other variables).

   1. In object-oriented programming, producing a particular
   object from its class template.  This involves allocation
   of a structure with the types specified by the template, and
   initialisation of instance variables with either default
   values or those provided by the class's constructor
   function.

   2. In logic programming, when unification binds a logic
   variable to some value.

   3. In type checking, when type inference binds a type
   variable to some type.

   4.  A specific representation of an object or
   artifact.  Examples of instantiations would be different images of
   an object, text translated into English and French or a video
   and a still image of a museum piece.

   (2015-02-08)