Barrier, n.
Etymology: [OE. barrere, barere, F. barrière, 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.
3 more senses
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.]
Shades of meaning
A bar is something that is or may be firmly fixed, ordinarily with intent to prevent entrance or egress; as, the bars of a prison cell; the bars of a wood-lot. A barrier obstructs, but is not necessarily impassable. Barrier is used of objects more extensive than those to which bar is ordinarily applied. A mountain range may be a barrier to exploration; but a mass of sand across the entrance to a harbor is called a bar. Discovered falsehood is a bar to confidence. Barricade has become practically a technical name for an improvised street fortification, and, unless in some way modified, is usually so understood. A parapet is a low or breast-high wall, as about the edge of a roof, terrace, etc., especially, in military use, such a wall for the protection of troops; a rampart is the embankment surrounding a fort, on which the parapet is raised; the word rampart is often used as including the parapet. Bulwark is a general word for any defensive wall or rampart; its only technical use at present is in nautical language, where it signifies the raised side of a ship above the upper deck, topped by the rail. Compare boundary; impediment.
Prepositions
A barrier to progress, against invasion; a barrier between nations.