The Collaborative International Dictionary of English v.0.48:

Tergiversate \Ter"gi*ver*sate\, v. i. [L. tergiversatus, p. p.
   of tergiversari to turn one's back, to shift; tergum back +
   versare, freq. of vertere to turn. See Verse.]
   To shift; to practice evasion; to use subterfuges; to
   shuffle. [R.] --Bailey.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tergiversate
    v 1: be deliberately ambiguous or unclear in order to mislead or
         withhold information [syn: beat around the bush,
         equivocate, tergiversate, prevaricate, palter]
    2: abandon one's beliefs or allegiances [syn: apostatize,
       apostatise, tergiversate]

Moby Thesaurus II by Grady Ward, 1.0:

59 Moby Thesaurus words for "tergiversate":
   alternate, apostatize, around the bush, back and fill, beat about,
   beg the question, bicker, boggle, cavil, change, choplogic,
   come round, desert, dither, do a flip-flop, do an about-face,
   dodge, duck, equivocate, evade, evade the issue, fence, fluctuate,
   have second thoughts, hedge, hem and haw, hum and haw,
   mince the truth, mince words, mystify, nitpick, obscure, oscillate,
   palter, parry, pendulate, pick nits, prevaricate, pussyfoot,
   quibble, rat, renounce, repudiate, shift, shilly-shally, shuffle,
   shy, sidestep, split hairs, teeter, totter, turn, vacillate, vary,
   waffle, waver, weasel, wheel, wobble