Source : Webster's Revised Unabridged Dictionary (1913)

Roadster \Road"ster\, n.
   1. (Naut.) A clumsy vessel that works its way from one
      anchorage to another by means of the tides. --Ham. Nav.
      Encyc.

   2. A horse that is accustomed to traveling on the high road,
      or is suitable for use on ordinary roads.

            A sound, swift, well-fed hunter and roadster.
                                                  --Thackeray.

   3. A bicycle or tricycle adapted for common roads rather than
      for the racing track.

   4. One who drives much; a coach driver. [Eng.]

   5. A hunter who keeps to the roads instead of following the
      hounds across country. [Eng. Slang.]

Source : WordNet®

roadster
     n 1: an open automobile having a front seat and a rumble seat
          [syn: {runabout}, {two-seater}]
     2: a small lightweight carriage; drawn by a single horse [syn:
        {buggy}]