KO, bar, bind, block, block up, blockade, bonnet, bung, cap, caulk, ceil, check valve, chink, choke, choke off, choke up, clincher, clog, clog up, close, cock, coif, congest, constipate, cork, cover, crown, crusher, dam, dam up, death stroke, deathblow, dome, end-all, ender, faucet, fill, fill up, final stroke, finisher, finishing stroke, foul, hat, hood, jam, kayo, kayo punch, knockout, knockout blow, last dab, lid, obstipate, obstruct, occlude, operculum, pack, peg, pin, plug, plug up, quietus, roof, roof in, sea cock, settler, sockdolager, spigot, spike, spile, spill, stanch, stay, stench, stop, stop up, stopgap, stopple, stuff, stuff up, tap, tip, top, valve
hindrance, prevention, preclusion, obstruction, stoppage, embolus, embolism, infarct, interruption, interception, interclusion, hindrance, impedition, retardment, retardation, embarrassment, oppilation, coarctation, stricture, restriction, restraint, inhibition, blockade, interference, interposition, obtrusion, discouragement, discountenance, impediment, let, obstacle, obstruction, knot, knag, check, hitch, contretemps, screw loose, grit in the oil, bar, stile, barrier, turnstile, turnpike, gate, portcullis, beaver dam, trocha, barricade, wall, dead wall, sea wall, levee breakwater, groyne, bulkhead, block, buffer, stopper
, boom, dam, weir, burrock, drawback, objection, stumbling-block, stumbling-stone, lion in the path, snag, snags and sawyers, encumbrance, incumbrance, clog, skid, shoe, spoke, drag, drag chain, drag weight, stay, stop, preventive, prophylactic, load, burden, fardel, onus, millstone round one's neck, impedimenta, dead weight, lumber, pack, nightmare, Ephialtes, incubus, old man of the sea, remora, difficulty, insuperable, obstacle, estoppel, ill wind, head wind, trammel, tether, hold back, counterpoise, damper, wet blanket, hinderer, marplot, killjoy, party pooper, party crasher, interloper, trail of a red herring, opponent, hindering, obstructive, obstruent, impeditive, impedient, intercipient, prophylactic, impedimentary, in the way of, unfavorable, onerous, burdensome, cumbrous, cumbersome, obtrusive, hindered, windbound, waterlogged, heavy laden, hard pressed, unassisted &c (assist), single-handed, alone, deserted, occurrent nubes.
closure, occlusion, blockade, shutting up, obstruction, embolus, contraction, infarction, constipation, obstipation, blind alley, blind corner, keddah, cul-de-sac, caecum, imperforation, imperviousness, impermeability, stopper
, closed, shut, operculated, unopened, unpierced, imporous, caecal, closable, imperforate, impervious, impermeable, impenetrable, impassable, unpassable, invious, pathless, wayless, untrodden, untrod, unventilated, air tight, water tight, hermetically sealed, tight, snug.
, stopple, plug, cork, bung, spike, spill, stopcock, tap, rammer, ram, ramrod, piston, stop-gap, wadding, stuffing, padding, stopping, dossil, pledget, tompion, tourniquet, cover, valve, vent peg, spigot, slide valve, janitor, doorkeeper, porter, warder, beadle, cerberus, ostiary.