The Collaborative International Dictionary of English v.0.48:

Cavil \Cav"il\ (k[a^]v"[i^]l), v. i. [imp. & p. p. Caviled or
   Cavilled; p. pr. & vb. n. Caviling or Cavilling.] [L.
   cavillari to practice jesting, to censure, fr. cavilla
   bantering jests, sophistry: cf. OF. caviller.]
   To raise captious and frivolous objections; to find fault
   without good reason.
   [1913 Webster]

         You do not well in obstinacy
         To cavil in the course of this contract. --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Caviling \Cav"il*ing\, a.
   Disposed to cavil; finding fault without good reason. See
   Captious.
   [1913 Webster]

         His depreciatory and caviling criticism. --Lewis.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

20 Moby Thesaurus words for "caviling":
   captious, carping, censorious, contrary, critic, demanding,
   exacting, faultfinding, finicky, fussy, hairsplitting,
   hypercritical, mean, niggling, nitpicking, overcritical, perverse,
   petty, picky, small