D defs.my
Entry 5 senses Webster, 1913

Barrier

/băr'-ē-ẽr/ · Bar·ri·er · IPA /ˈbæɹi.ɚ/
01 n. A carpentry obstruction, stockade, or other obstacle made in a passage in order to stop an enemy.
  1. 1.
    A carpentry obstruction, stockade, or other obstacle made in a passage in order to stop an enemy.(Fort.)
  2. 2.
    A fortress or fortified town, on the frontier of a country, commanding an avenue of approach.
  3. 3.
    A fence or railing to mark the limits of a place, or to keep back a crowd.
    “No sooner were the barriers opened, than he paced into the lists.” Sir W. Scott.
  4. 4.
    Any obstruction; anything which hinders approach or attack.
  5. 5.
    Any limit or boundary; a line of separation.
    “'Twixt that [instinct] and reason, what a nice barrier!” Pope.
Phrases & compounds
Barrier gate — a heavy gate to close the opening through a barrier.
Barrier reef — a form of coral reef which runs in the general direction of the shore, and incloses a lagoon channel more or less extensive.
To fight at barriers — to fight with a barrier between, as a martial exercise.