[1] : The Collaborative International Dictionary of English v.0.48

unifier \u"nifi`er\, n.
   one who, or that which, unifies; as, a natural law is a
   unifier of phenomena.
   1913 webster

[2] : The Free On-line Dictionary of Computing (27 SEP 03)

unifier
     
        the unifier of a set of expressions is a set of substitutions
        of terms for variables such that the expressions are all
        equal.
     
        see also most general unifier, unification.
     
        1994-12-06
     
     
see also:
most general unifier unification 

Unifier >> U Words
Unifier, definition of term: Unifier
unifier_pag1.html