thwart

Synonyms: baffle balk beat bilk check circumvent confuse counter crab cramp crimp cross curb dash defeat disappoint ditch dodge double-cross duck foil foul up frustrate give the slip hold up impede louse up match obstruct oppose outwit pit play off prevent queer restrain ruin scotch skin snafu stymie take down take wind out of trammel upset upset one’s apple cart

Antonyms: aid assist encourage forward help