The Collaborative International Dictionary of English v.0.48:

odometer \o*dom"e*ter\ ([-o]*d[o^]m"[-e]*t[~e]r), n. [Gr.
   "odo`metron, "odo`metros, an instrument for measuring
   distance; "odo`s way + me`tron measure: cf. F. odom['e]tre,
   hodom['e]tre. See also hodometer.]
   An instrument attached to a vehicle or connected, as by a
   flexible cable, to the wheel of a vehicle, which measures the
   distance traversed.
   [1913 Webster]

   2. A hodometer.
      [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

odometer
    n 1: a meter that shows mileage traversed [syn: odometer,
         hodometer, mileometer, milometer]