impede, obstruct, interfere with, check, retard, fetter, block, thwart, bar, clog, encumber, burden, cripple, handicap, cramp, preclude, inhibit, debar, shackle, interrupt, arrest, contravene, curb, resist, oppose, baffle, muzzle, balk, deter, hamper, stand in the way of, frustrate, nullify, checkmate, outwit, foil, entangle, stop, counteract, offset, neutralize, derange, tie up, hold up, repress, obviate, embarrass, delay, defer, postpone, keep back, set back, dam, close, box in, end, terminate, shut out, stay, choke, intercept, overreach, bottleneck, entrap, defeat, interpose, trammel, trap, antagonize, control, conflict with, deadlock, hold from, hold back, repulse, clash with, circumscribe, be an obstacle to, be an impediment to, repel, cross, exclude, limit, keep in bounds, shorten, hamstring, filibuster, go against, prohibit, withhold, forestall, hedge, stem, slow down, stall, bring to a standstill, forbid, cause to delay, pinion, disallow, smother, stanch, disappoint, spoil, throttle, countervail, gag, bind hand and foot, annul, silence, invalidate, vitiate, cancel out, hobble, constrict, cage, corner, detain, deprive, stalemate, taboo, suspend, render difficult, set against, pit against, put back, clip one's wings*, fly in the face of*, tie one's hands*, set one's face against*, get in the way of*, hold up*, jam*, throw a monkey wrench into the works*, snafu*, scotch*, spike one's guns*, hang fire*, bog down*, stymie*, put the lid on*, hang up*, knock the bottom out of*, knock the props from under*; see also prevent, restrain 1.

Antonyms help*, assist*, aid.