Pronunciation: (kom"yu-tā'shun), [key]
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 commuta'tion 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.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.