Pronunciation: (bar'ē-ur),[key] —n. 1. anything built or serving to bar passage, as a railing, fence, or the like: People may pass through the barrier only when their train is announced. 2. any natural bar or obstacle: a mountain barrier. 3. anything that restrains or obstructs progress, access, etc.: a trade barrier. 4. a limit or boundary of any kind: the barriers of caste. 5. Physical Geog.an antarctic ice shelf or ice front.
6. See barrier beach. 7. barriers,Hist.the palisade or railing surrounding the ground where tourneys and jousts were carried on.
8. Archaic.a fortress or stockade.