barriern.[OE. barrere, barere, F. barrire, 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. 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. Any obstruction; anything which hinders approach or attack.(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.]()n.[Native name, fr. Sp. barrigudo big-bellied.] (Zol.) A large, dark-colored, South American monkey, of the genus Lagothrix, having a long prehensile tail.()