The Collaborative International Dictionary of English v.0.48:

Commutative \Com*mut"a*tive\, a. [CF. F. commutatif.]
   1. Relative to exchange; interchangeable; reciprocal. --
      Com*mut"a*tive"ly, adv.
      [1913 Webster]

            Rich traders, from their success, are presumed . . .
            to have cultivated an habitual regard to commutative
            justice.                              --Burke.
      [1913 Webster]

   2. (Math.) having the property of commutativity.
      [PJC]