Com·mute v. t. [imp. & p. p. Commuted; p. pr. & vb. n. Commuting.]
1. To exchange; to put or substitute something else in place of, as a smaller penalty, obligation, or payment, for a greater, or a single thing for an aggregate; hence, to lessen; to diminish; as, to commute a sentence of death to one of imprisonment for life; to commute tithes; to commute charges for fares.
The sounds water and fire, being once annexed to those two elements, it was certainly more natural to call beings participating of the first =\“watery”, and the last “fiery”, than to commute the terms, and call them by the reverse.\= --J. Harris
The utmost that could be obtained was that her sentence should be commuted from burning to beheading. --Macaulay.