The Collaborative International Dictionary of English v.0.48:

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.
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   2. To exchange; substitute one thing for another.
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            We go on chopping and changing our friends.
                                                  --L'Estrange.
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   To chop logic, to dispute with an affected use of logical
      terms; to argue sophistically.
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