Source : Webster's Revised Unabridged Dictionary (1913)

Unification \U`ni*fi*ca"tion\, n. [See {Unify}.]
   The act of unifying, or the state of being unified.

         Unification with God was the final aim of the
         Neoplatonicians.                         --Fleming.

Source : WordNet®

unification
     n 1: an occurrence that involves the production of a union [syn:
          {fusion}, {merger}]
     2: the state of being joined or united or linked; "there is
        strength in union" [syn: {union}] [ant: {separation}]
     3: the act of making or becoming a single unit; "the union of
        opposing factions"; "he looked forward to the unification
        of his family for the holidays" [syn: {union}, {uniting},
        {conjugation}, {jointure}] [ant: {disunion}]

Source : Free On-Line Dictionary of Computing

unification
     
         The generalisation of {pattern matching} that is
        the {logic programming} equivalent of {instantiation} in
        {logic}.  When two {term}s are to be unified, they are
        compared.  If they are both constants then the result of
        unification is success if they are equal else failure.  If one
        is a variable then it is bound to the other, which may be any
        term (which satisfies an "{occurs check}"), and the
        unification succeeds.  If both terms are structures then each
        pair of sub-terms is unified {recursive}ly and the unification
        succeeds if all the sub-terms unify.
     
        The result of unification is either failure or success with a
        set of variable bindings, known as a "{unifier}".  There may
        be many such unifiers for any pair of terms but there will be
        at most one "{most general unifier}", other unifiers simply
        add extra bindings for sub-terms which are variables in the
        original terms.
     
        (1995-12-14)