Com*mute" (k&obreve;m*mūt"), v. t. [imp. & p. p. Commuted; p. pr. & vb. n. Commuting.] [L. commutare, -mutatum; com- + mutare to change. See Mutation.] 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.

Com*mute", v. i. 1. To obtain or bargain for exemption or substitution; to effect a commutation.

He . . . thinks it unlawful to commute, and that he is bound to pay his vow in kind.
Jer. Taylor.

2. To pay, or arrange to pay, in gross instead of part by part; as, to commute for a year's travel over a route.

• To travel from one's home (usually in the suburbs of a city) to one's workplace (usually in the city itself, or in another city) to go to work, or vice versa.
  
• (Mathematics): to engage in a commutative operation.
  
• (Finance): To pay put the lump-sum present value of an annuity.
  
• (Criminology): To reduce the sentence previously given for a criminal offense.