puzzled

Synonyms: at a loss at sea baffled bewildered bollixed clueless come apart come unzipped discombobulated dopey doubtful floored foggy fouled up hung up in a fog lost loused up messed up mind-blown mixed up mucked up mystified nonplussed perplexed rattled screwed up shook shook up spaced out stuck stumped thrown unglued without a clue

Antonyms: aware certain cognizant sure