N contention, strife, contest, contestation, struggle, belligerency, opposition, controversy, polemics, debate, war of words, logomachy, litigation, paper war, high words, sparring, competition, rivalry, corrivalry, corrivalship, agonism, concours, match, race, horse racing, heat, steeple chase, handicap, regatta, field day, sham fight, Derby day, turf, sporting, bullfight, tauromachy, gymkhana, boat race, torpids, wrestling, greco-roman wrestling, pugilism, boxing, fisticuffs, the manly art of self-defense, spar, mill, set-to, round, bout, event, prize fighting, quarterstaff, single stick, gladiatorship, gymnastics, jiujitsu, jujutsu, kooshti, sumo, athletics, athletic sports, games of skill, shindy, fracas, clash of arms, tussle, scuffle, broil, fray, affray, affrayment, velitation, colluctation, luctation, brabble, brigue, scramble, melee, scrimmage, stramash, bushfighting, free fight, stand up fight, hand to hand, running fight, conflict, skirmish, rencounter, encounter, rencontre, collision, affair, brush, fight, battle, battle royal, combat, action, engagement, joust, tournament, tilt, tilting, tournay, list, pitched battle, death struggle, struggle for life or death, life or death struggle, Armageddon, hard knocks, sharp contest, tug of war, naval engagement, naumachia, sea fight, duel, duello, single combat, monomachy, satisfaction, passage d'armes, passage of arms, affair of honor, triangular duel, hostile meeting, digladiation, deeds of arms, feats of arms, appeal to arms, pugnacity, combativeness, bone of contention, contending, together by the ears, at loggerheads, at war, at issue, competitive, rival, belligerent, contentious, combative, bellicose, unpeaceful, warlike, quarrelsome, pugnacious, pugilistic, gladiatorial, palestric, palestrical, a verbis ad verbera, a word and a blow, a very pretty quarrel as it stands, commune periculum concordiam parit, lis litem generat.

For further exploring for "sparring" in Webster Dictionary Online