In criminal law . Change; substitution . The substitution of one punishment for another, after conviction of the party subject to it. The change of a punishment from a greater to a less; as from hanging to imprisonment . Commutation of a punishment is not a conditional pardon , but the substitution of a lower for a higher grade of punishment, and is presumed to be for the culprit’s benefit. In re Victor, 31 Ohio St. 207; Ex parte Janes, 1 Nev. 321; Rich v. Chamberlain , 107 Mich. 381, 65 N. W. 235.