Source : Webster's Revised Unabridged Dictionary (1913)

Cab \Cab\ (k[a^]b), n. [Abbrev. fr. cabriolet.]
   1. A kind of close carriage with two or four wheels, usually
      a public vehicle. ``A cab came clattering up.''
      --Thackeray.

   Note: A cab may have two seats at right angles to the
         driver's seat, and a door behind; or one seat parallel
         to the driver's, with the entrance from the side or
         front.

   {Hansom cab}. See {Hansom}.

   2. The covered part of a locomotive, in which the engineer
      has his station. --Knight.

Hansom \Han"som\, n., Hansom cab \Han"som cab`\ [From the name
   of the inventor.]
   A light, low, two-wheeled covered carriage with the driver's
   seat elevated behind, the reins being passed over the top.

         He hailed a cruising hansom . . . `` 'Tis the gondola
         of London,'' said Lothair.               --Beaconsfield.

Source : WordNet®

hansom cab
     n : a two-wheeled horse-drawn covered carriage with the driver's
         seat above and behind the passengers [syn: {hansom}]