commutation

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A substitution, exchange, or interchange.
2. n. The substitution of one kind of payment for another.
3. n. The payment substituted.
4. n. The travel of a commuter.
5. n. Electricity Conversion of alternating to unidirectional current.
6. n. Electricity Reversal of current direction.
7. n. Law Reduction of a penalty to a less severe one.

Century Dictionary and Cyclopedia

1. n. A passing from one state to another; alteration; change.
2. n. The act of giving one thing for another; exchange; barter.
3. n. The act of substituting one thing for another; substitution.
4. n. Specifically— In law, the change of a penalty or punishment from a greater to a less, as banishment instead of death.
5. n. The substitution of one sort of payment for another, or of a money payment in lieu of the performance of compulsory duty or labor, or of a single payment in lieu of a number of successive payments, usually at a reduced rate. See commutation-ticket.
6. n. Milit., the money value of allowances, such as quarters, fuel, forage, etc., taken in place of them.

Wiktionary

1. n. obsolete A passing from one state to another; change; alteration; mutation.
2. n. obsolete The act of giving one thing for another; barter; exchange.
3. n. Substitution of one thing for another; interchange.
4. n. Specifically, the substitution of one kind of payment for another, especially a switch to monetary payment from obligations of labour.
5. n. law The change to a lesser penalty or punishment by the State
6. n. linguistics Substitution, as a means of discriminating between phonemes.
7. n. electronics The reversal of an electric current.

GNU Webster's 1913

1. n. rare A passing from one state to another; change; alteration; mutation.
2. n. obsolete The act of giving one thing for another; barter; exchange.
3. n. (Law) The change of a penalty or punishment by the pardoning power of the State.
4. n. A substitution, as of a less thing for a greater, esp. a substitution of one form of payment for another, or one payment for many, or a specific sum of money for conditional payments or allowances.
5. n. regular travel from a place of residence to a place where one's daily work is performed; commuting. Most often, such travel is performed between a suburb and a nearby city.

WordNet 3.0

1. n. (law) the reduction in severity of a punishment imposed by law
2. n. a warrant substituting a lesser punishment for a greater one
3. n. the travel of a commuter
4. n. the act of putting one thing or person in the place of another: