Barrier \Bar"ri*er\, n. [OE. barrere, barere, F. barri[`e]re, fr. barre bar. See Bar, n.]

1. (Fort.) A carpentry obstruction, stockade, or other obstacle made in a passage in order to stop an enemy.

2. A fortress or fortified town, on the frontier of a country, commanding an avenue of approach.

3. pl. 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. An any obstruction; anything which hinders approach or attack. ``Constitutional barriers.'' --Hopkinson.

5. Any limit or boundary; a line of separation.

'Twixt that [instinct] and reason, what a nice barrier ! --Pope.

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. [Obs.]

Source: Webster's Revised Unabridged Dictionary (1913)