Commutation meaning : A passing from one state to another; change; alteration; mutation. The act of giving one thing for another; barter; exchange. Substitution of one thing for another; interchange. Specifically, the substitution of one kind of payment for another, especially a switch to monetary payment from obligations of labour. The change to a lesser penalty or punishment by the State Substitution, as a means of discriminating between phonemes. The reversal of an electric current.