1the action or process of commuting a judicial sentence:a commutation of her sentence
the conversion of a legal obligation or entitlement into another form, e.g. the replacement of an annuity or series of payments by a single payment:the commutation of dues into money rentsmaking a one-off lump sum in commutation of your pension rights
2the process of commutating an electric current.
3 Mathematics the property of having a commutative relation.
late Middle English (in the sense 'exchange, barter', later 'alteration'): from Latin commutatio(n-), from commutare 'exchange, interchange' (see commute). sense 1 dates from the late 16th century
commutation in other Oxford dictionaries
Definition of commutation in the US English dictionary