To travel as a commuter. To make substitution or exchange. To serve as a substitute. To pay in gross, usually at a reduced rate, rather than in individual payments. Mathematics & Logic To satisfy or engage in a commutative operation. To substitute (one thing for another); exchange. To change (a penalty, debt, or payment) to a less severe one. An act or instance of commuting, especially the trip made by a commuter: a 22-mile commute; an easy commute.