Synonyms of nonplussed

1 Syllable
floor, stick, get, balk, stun, thwart, beat, throw, daze, stump, faze
2 Syllables
muddle, boggle, stagger, flurry, puzzled, puzzle, dumbfound, stymie, distraught, mind-blown, astound, rattle, fluster, confound, clueless, baffle, unglued, dismay
3 Syllables
astonish, mystify, bollixed, buffalo, confused, disconcert, discomfit, bewilder, wonderstruck, frustrate, glassy-eyed, embarrass
4 Syllables
muddle-headed, unsurprised, paralyze, disconcerted, overcome
5 Syllables
discountenance