/ ˌkɒmjuˈteɪʃn; NAmE ˌkɑːm-/ noun [ C , U ]
1.
( law ) the act of making a punishment less severe :
a commutation of the death sentence to life imprisonment
2.
( finance ) the act of replacing one method of payment with another; a payment that is replaced with another
••
WORD ORIGIN
late Middle English (in the sense exchange, barter , later alteration ): from Latin commutatio(n-) , from commutare exchange, interchange from com- altogether + mutare to change. Sense 1 dates from the late 16th cent.