fence

bar, pale, paling

block, chain, clog, crimp, deterrent, drag, embarrassment, encumbrance, handicap, hindrance, hurdle, impediment, inhibition, interference, let, obstacle, obstruction, roadblock, stop, stumbling block, trammel

fetter, hobble, manacle, shackle(s)

constraint, curb, restraint, snag

buffer, bulwark, bumper, cushion, dam, fender, pad, rampart

avert, prevent

oppose, resist, withstand

battle, contend, fight, war

conserve, preserve, save

buffer, palisade, picket, wall