1. An exchange or replacement.
2. Criminal law. The executive’s substitution in a particular case of a less severe punishment for a more severe one that has already been judicially imposed on the defendant. Cf. PARDON; REPRIEVE. [Cases: Pardon and Parole 28. C.J.S. Pardon and Parole §§ 4, 34–41.]
3. Commercial & civil law. The substitution of one form of payment for the other. — commute, vb. — commutative, adj.