barrier: Meaning and Definition of

bar•ri•er

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. an antarctic ice shelf or ice front.
6. See
7. the palisade or railing surrounding the ground where tourneys and jousts were carried on.
8. a fortress or stockade.