Source : Webster's Revised Unabridged Dictionary (1913)

Caviler \Cav"il*er\ or Caviller \Cav"il*ler\ (-[~e]r), n.
   One who cavils.

         Cavilers at the style of the Scriptures. --Boyle.

Source : WordNet®

caviller
     n : a disputant who quibbles; someone who raises annoying petty
         objections [syn: {quibbler}, {caviler}, {pettifogger}]