Source : Webster's Revised Unabridged Dictionary (1913)

Commuter \Com*mut"er\, n.
   One who commutes; especially, one who commutes in traveling.

Source : WordNet®

commuter
     n 1: a passenger train that is ridden primarily by commuters
          [syn: {commuter train}]
     2: someone who travels regularly from home in a suburb to work
        in a city