Source : Webster's Revised Unabridged Dictionary (1913)

Odometer \O*dom"e*ter\, n. [Gr. ?, ?, an instrument for
   measuring distances; ? way + ? measure: cf. F. odom[`e]tre,
   hodom[`e]tre.]
   An instrument attached to a vehicle, to measure the distance
   traversed; also, a wheel used by surveyors, which registers
   the miles and rods traversed. -- {Od`o*met"ric*al}, a.

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.]
   An instrument attached to the wheel of a vehicle, to measure
   the distance traversed; also, a wheel used by surveyors,
   which registers the miles and rods traversed.

Source : WordNet®

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