Source : Webster's Revised Unabridged Dictionary (1913)

Chop \Chop\, v. t. [Cf. D. koopen to buy. See {Cheapen}, v. t.,
   and cf. {Chap}, v. i., to buy.]
   1. To barter or truck.

   2. To exchange; substitute one thing for another.

            We go on chopping and changing our friends.
                                                  --L'Estrange.

   {To chop logic}, to dispute with an affected use of logical
      terms; to argue sophistically.