—v.t. 1. to change (a prison sentence or other penalty) to a less severe one: The death sentence was commuted to life imprisonment. 2. to exchange for another or for something else; give and take reciprocally; interchange.
3. to change: to commute base metal into gold. 4. to change (one kind of payment) into or for another, as by substitution.
—v.i. 1. to travel regularly over some distance, as from a suburb into a city and back: He commutes to work by train. 2. to make substitution.
3. to serve as a substitute.
4. to make a collective payment, esp. of a reduced amount, as an equivalent for a number of payments.
5. Math.to give the same result whether operating on the left or on the right.
—n. 1. a trip made by commuting: It's a long commute from his home to his office. 2. an act or instance of commuting.