The Collaborative International Dictionary of English v.0.48:

Equivocate \E*quiv"o*cate\, v. i. [imp. & p. p. Equivocated;
   p. pr. & vb. n. Equivocating.] [L. aequivocatus, p. p. of
   aequivocari to be called by the same name, fr. L. aequivocus:
   cf. F. ['e]quivoquer. See Equivocal, a.]
   To use words of equivocal or doubtful signification; to
   express one's opinions in terms which admit of different
   senses, with intent to deceive; to use ambiguous expressions
   with a view to mislead; as, to equivocate is the work of
   duplicity.
   [1913 Webster]

         All that Garnet had to say for him was that he supposed
         he meant to equivocate.                  --Bp.
                                                  Stillingfleet.

   Syn: To prevaricate; evade; shuffle; quibble. See
        Prevaricate.
        [1913 Webster]