Synonyms and related words :
addled, at a loss, at a nonplus, at a stand, at a standstill, at an impasse, baffled, bamboozled, beat, bewildered, buffaloed, confounded, dazed, floored, fuddled, in a dilemma, in suspense, licked, muddled, mystified, nonplussed, on tenterhooks, perplexed, puzzled, stuck, thrown