Source : Webster's Revised Unabridged Dictionary (1913)

Borough \Bor"ough\, n. [OE. burgh, burw, boru, port, town,
   burrow, AS. burh, burg; akin to Icel., Sw., & Dan. borg, OS.
   & D. burg, OHG. puruc, purc, MHG. burc, G. burg, Goth.
   ba['u]rgs; and from the root of AS. beorgan to hide, save,
   defend, G. bergen; or perh. from that of AS. beorg hill,
   mountain. [root]95. See {Bury}, v. t., and cf. {Burrow},
   {Burg}, {Bury}, n., {Burgess}, {Iceberg}, {Borrow}, {Harbor},
   {Hauberk}.]
   1. In England, an incorporated town that is not a city; also,
      a town that sends members to parliament; in Scotland, a
      body corporate, consisting of the inhabitants of a certain
      district, erected by the sovereign, with a certain
      jurisdiction; in America, an incorporated town or village,
      as in Pennsylvania and Connecticut. --Burrill. Erskine.

   2. The collective body of citizens or inhabitants of a
      borough; as, the borough voted to lay a tax.

   {Close borough}, or {Pocket borough}, a borough having the
      right of sending a member to Parliament, whose nomination
      is in the hands of a single person.

   {Rotten borough}, a name given to any borough which, at the
      time of the passage of the Reform Bill of 1832, contained
      but few voters, yet retained the privilege of sending a
      member to Parliament.

Borough \Bor"ough\, n. [See {Borrow}.] (O. Eng. Law)
      (a) An association of men who gave pledges or sureties to
          the king for the good behavior of each other.
      (b) The pledge or surety thus given. --Blackstone.
          Tomlins.

Source : WordNet®

borough
     n 1: one of the administrative divisions of a large city
     2: an English town that forms the constituency of a member of
        Parliament