fence, hurdle, barricade, roadblocks, wall, obstacle, glass ceiling, berm, stumbling block, retaining wall, impediment, bridge, bollard, chasm, cordon, bottleneck, gates, sound barrier, rampart, threshold, crossing, firebreak, chainlink fence, railing, cordon sanitaire, levee, checkpoints, hindenburg line, seawall, logjam, resistance, palings, breakwater, taboos, hindrance, barbed wire, obstructions, buffer, covalent bond, divider, boundary, blockade, guardrail, rubicon, settlements, contiguity, walkway, mark, snowshed, restriction, iron curtain, dam, firewalls, causeway, constraint, mona passage, factor, moat, judaization, footbridge, doorframe, splint bone, gap, tunnel, battering ram, spermatozoon, drawbridge, sluiceway, reseals, noseband, chunnel, falsework, shield, pylons, palisade, fishway, gateway, sesamoid bone, zona pellucida, window, maginot line, abutment, groyne, semipermeable membrane, ingression, interlayer, overpass, curbstone, fortifications, marker, divide, floodgate, frontiers, bascule, chokepoint, prerequisite, borders, kerbing, archway, dike, shatterproof glass, scaffolding, barriers, obstacles, roadblock, bulwark, deterrent, safeguard, disadvantage, disincentive, handicap, hurdles, impediments, challenge, inducement, advantage, drawback, hindrances, epitaxial, schottky, nonlinear, photoconductive, biomimetic, combinational, scattering, silicon, viscoelastic, dissipative, doped, ferroelectric, impedance, overlay, semipermeable, dielectric, dispersive, electrode, lossy

barricade, blood-brain barrier, breakwater, bulwark, bulwarks, curtain, dam, dike, fence, fencing, fender, grate, grating, groin, groyne, hurdle, ideological barrier, jetty, language barrier, levee, mole, movable barrier, rail, railing, revetment, roadblock, seawall, starting gate, starting stalls, wing

., abatis, abattis, achoerodus gouldii, act as, appalachians, appalachian mountains, bamboo curtain, barricade, blood-brain barrier, breakthrough, break through, cape canaveral, cape kennedy, chicane, color bar, color line, colour bar, colour line, crack, crash, crash barrier, curtain, dam, dike, divide, divided highway, door, dual carriageway, embargo, fence, fencing, fender, gate, giant pigfish, grate, grating, hatch, hatteras island, hurdle, ideological barrier, iron curtain, jim crow, language barrier, levee, line of defence, line of defense, movable barrier, pigfish, rail, railing, rain shadow, revetment, roadblock, separate, shielding, sluice, starting gate, starting stalls, trade embargo, trade stoppage, wing

impediment, impedimenta, mechanism, obstacle, obstruction

roadblock