The Collaborative International Dictionary of English v.0.48:

Pettifog \Pet"ti*fog\, v. t.
   To advocate like a pettifogger; to argue trickily; as, to
   pettifog a claim. [Colloq.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pettifog \Pet"ti*fog\, v. i. [imp. & p. p. Pettifogged; p. pr.
   & vb. n. Pettifogging.] [Petty + fog to pettifog.]
   1. To do a petty business as a lawyer; also, to do law
      business in a petty or tricky way. "He takes no money, but
      pettifogs gratis." --S. Butler.
      [1913 Webster]

   2. To debate or quarrel over unimportant, trifling matters.
      [PJC]

   3. To use subterfuge, deception, or flattery for any purpose;
      to practice chicanery.
      [PJC]

WordNet (r) 3.0 (2006):

pettifog
    v 1: argue over petty things; "Let's not quibble over pennies"
         [syn: quibble, niggle, pettifog, bicker,
         squabble, brabble]