The Collaborative International Dictionary of English v.0.48:

Equivocator \E*quiv"o*ca`tor\, n.
   One who equivocates.
   [1913 Webster]

         Here's an equivocator that could swear in both the
         scales against either scale, yet could not equivocate
         to heaven.                               --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

equivocator
    n 1: a respondent who avoids giving a clear direct answer [syn:
         hedger, equivocator, tergiversator]