fortress

/ˈfɔɹ.tɹəs/

IPA: /F AO1 R T R AH0 S/

noun
  1. 1

    A fortified place; a large and permanent fortification, sometimes including a town; for example a fort, a castle; a stronghold; a place of defense or security.

  2. 2

    A position that, if obtained by the weaker side, will prevent penetration by the opposing side, generally achieving a draw.

verb
  1. 1

    To furnish with a fortress or with fortresses; to guard, to fortify.

Source: https://en.wiktionary.org/wiki/fortress