Source : Webster's Revised Unabridged Dictionary (1913)

Apartment \A*part"ment\, n. [F. appartement; cf. It.
   appartamento, fr. appartare to separate, set apart; all fr.
   L. ad + pars, partis, part. See {Apart}.]
   1. A room in a building; a division in a house, separated
      from others by partitions. --Fielding.

   2. A set or suite of rooms. --De Quincey.

   3. A compartment. [Obs.] --Pope.

Source : WordNet®

apartment
     n : a suite of rooms usually on one floor of an apartment house
         [syn: {flat}]