The Collaborative International Dictionary of English v.0.48:

Fusion \Fu"sion\, n. [L. fusio, fr. fundere, fusum to pour,
   melt: cf. F. fusion. See Fuse, v. t., aud cf, Foison.]
   1. The act or operation of melting or rendering fluid by
      heat; the act of melting together; as, the fusion of
      metals.
      [1913 Webster]

   2. The state of being melted or dissolved by heat; a state of
      fluidity or flowing in consequence of heat; as, metals in
      fusion.
      [1913 Webster]

   3. The union or blending together of things, as, melted
      together.
      [1913 Webster]

            The universal fusion of races, languages, and
            customs . . .
            had produced a corresponding fusion of creeds. --C.
                                                  Kingsley.
      [1913 Webster]

   Watery fusion (Chem.) the melting of certain crystals by
      heat in their own water of crystallization.
      [1913 Webster]

   4. (Biol.) The union, or binding together, of adjacent parts
      or tissues.
      [1913 Webster]

WordNet (r) 3.0 (2006):

fusion
    n 1: an occurrence that involves the production of a union [syn:
         fusion, merger, unification]
    2: the state of being combined into one body [syn: coalition,
       fusion]
    3: the merging of adjacent sounds or syllables or words
    4: a nuclear reaction in which nuclei combine to form more
       massive nuclei with the simultaneous release of energy [syn:
       fusion, nuclear fusion, nuclear fusion reaction]
    5: the combining of images from the two eyes to form a single
       visual percept [syn: fusion, optical fusion]
    6: correction of an unstable part of the spine by joining two or
       more vertebrae; usually done surgically but sometimes done by
       traction or immobilization [syn: fusion, spinal fusion]
    7: the act of fusing (or melting) together

The Free On-line Dictionary of Computing (19 January 2023):

FUSION

   Software package supplied by Network Research Corporation
   claiming to connect various different configurations of LAN.


The Free On-line Dictionary of Computing (19 January 2023):

fusion
vertical loop combination

    A program transformation where a composition
   of two functions is replaced by in-lining them and combining
   their bodies.  E.g.

    f x = g (h x)	==>	f x = g (2 * x)
    g x = x + 1	 f x = 2 * x + 1
    h x = 2 * x

   This has the beneficial effect of reducing the number of
   function calls.  It can be especially useful where the
   intermediate result is a large data structure which can be
   eliminated.

   See also vertical loop combination.

   (1994-12-05)