Definition of "ribat"

(chiefly historical) A border or frontier guardpost.

(chiefly historical) A caravanserai or inn in, converted from, or resembling such a guardpost.

(historical) The duty of some men to serve at such posts.

(Islam, figurative) The duty of all Muslims to defend and/or retake Islamic lands.  examples

A Sufi monastery.  examples

(chiefly historical) An Islamic convent.