Source : Webster's Revised Unabridged Dictionary (1913)

Apartment house \A*part"ment house\
   A building comprising a number of suites designed for
   separate housekeeping tenements, but having conveniences,
   such as heat, light, elevator service, etc., furnished in
   common; -- often distinguished in the United States from a
   {flat house}.

Source : WordNet®

apartment house
     n : a building that is divided into apartments [syn: {apartment
         building}]