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." "The utmost that could be obtained was that her sentence should be commuted from burning to beheading."
...