THESAURUS
obstructionist
bitter-ender, brawler, defendant, diehard, disputant, dissentient, dissident, filibuster, filibusterer, frustrater, hinderer, impeder, intransigent, irreconcilable, last-ditcher, litigant, marplot, naysayer, negativist, noncooperator, objector, obstructer, obstructive, opposer, oppositionist, plaintiff, protester, quarreler, resister, scrapper, thwarter, wrangler
ROGET THESAURUS
obstructionist
Opponent
N
opponent, 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.