adversary, adversative, adverse, alien, antagonist, antagonistic, anti, antipathetic, antithetic, assailant, clashing, combatant, competitive, competitor, con, conflicting, contender, contestant, contradictory, contrary, counter, counteragent, cross, disaccordant, disputant, dissentient, enemy, foe, fractious, hostile, inimical, match, negative, noncooperative, obstinate, opposed, opposer, opposing, opposite, oppositional, oppositive, oppugnant, overthwart, perverse, recalcitrant, refractory, repugnant, rival, the opposition, uncooperative, unfavorable, unfriendly, unpropitious
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.
, antagonist, adversary, adverse party, opposition, enemy, the other side, assailant, oppositionist, obstructive, brawler, wrangler, brangler, disputant, filibuster, obstructionist, malcontent, Jacobin, Fenian, demagogue, reactionist, rival, competitor, bete noir.
enemy, antagonist, foe, foeman, open enemy, bitter enemy, opponent
, back friend, public enemy, enemy to society, every hand being against one, he makes no friend who never made a foe, with friends like that, who needs enemies?, Lord protect me from my friends, I can protect myself from my enemies.