/kom'yeuh tay"sheuhn/ , n.
1. the act of substituting one thing for another; substitution; exchange.
2. the changing of a prison sentence or other penalty to another less severe.
3. the act of commuting, as to and from a place of work.
4. the substitution of one kind of payment for another.
5. Elect. the act or process of commutating.
6. Also called commutation test . Ling. the technique, esp. in phonological analysis, of substituting one linguistic item for another while keeping the surrounding elements constant, used as a means of determining the constituent units in a sequence and their contrasts with other units.
[ 1400-50; late ME commutacioun commutation- (s. of commutatio ) change. See COMMUTE, -ATION ]