Definition of "apartment"

apartment

/əˈpɑːt.mənt/

noun
plural apartments
1. (chiefly Canada, US, Australia, Philippines) A complete domicile occupying only part of a building, especially one for rent; a flat.
  Quotations
  I am Jonathan. I am in apartment B4. — I am in apartment C2. Audio (US)(file)
  2016, VOA Learning English (public domain)
2. (archaic) A suite of rooms within a domicile, designated for a specific person or persons and including a bedroom.
  Quotations
  By this contrivance I got into the inmost court; and, lying down upon my side, I applied my face to the windows of the middle stories, which were left open on purpose, and discovered the most splendid apartments that can be imagined. There I saw the empress and the young princes in their several lodgings, with their chief attendants about them.
  1726 October 28, [Jonathan Swift], Travels into Several Remote Nations of the World. […] [Gulliver’s Travels], volume I, London: […] Benj[amin] Motte, […], part I (A Voyage to Lilliput)
3. (obsolete) A division of an enclosure that is separate from others; a compartment
  Quotations
  The specification described the ordinary fare-box used in street cars and omnibuses, consisting of two apartments, the one directly above the other.... [T]he passenger deposited his fare in an aperture in the top of the upper apartment. It fell upon and was arrested by a movable platform.... This platform turned on an axis acted on by a lever. When turned, the fare fell into the lower apartment, which was a receptacle for holding the fares accumulated....
  1883 April 23, Slawson v. Grand Street R. Co., 107 U.S. 649, 2 S.Ct. 663, 664
4. (computing, COM) A conceptual space used for separation in the threading architecture. Objects in one apartment cannot directly access those in another, but must use a proxy.