The Collaborative International Dictionary
Commutable \Com*mut"a*ble\, a. [L. commutabilis.] Capable of being commuted or interchanged.
The predicate and subject are not commutable.
--Whately.
Wiktionary
a. Capable of being commuted.
WordNet
adj. subject to alteration or change; "the death sentence was commutable to life imprisonment" [ant: incommutable]
capable of being exchanged for another or for something else that is equivalent [syn: substitutable]
Usage examples of "commutable".
Although the journey between Amsterdam and The Hague was easily commutable daily, Sanglier took a suite at the Amstel Intercontinental.
Still within a commutable distance of LA—well, by jet—but far enough away that he almost never had to have conversations with people about points and gross net deficits (except, occasionally, with his agent) the ranch was more of a retreat than it was merely a home.