a passing from one state to another; change; alteration; mutation.-the act of giving one thing for another; barter; exchange.-the change of a penalty or punishment by the pardoning power of the state; as, the commutation of a sentence of death to banishment or imprisonment.-a substitution, as of a less thing for a greater, esp. a substitution of one form of payment for another, or one payment for many, or a specific sum of money for conditional payments or allowances; as, commutation of tithes; commutation of fares; commutation of copyright; commutation of rations.