say what?
US /seɪ wʌt/
UK /seɪ wʌt/

1.
뭐라고?, 뭐?
used to express surprise or to ask someone to repeat something because you did not hear or understand it
:
•
I just won the lottery! Say what?
나 방금 복권 당첨됐어! 뭐라고?
•
You want me to work on Saturday? Say what?
토요일에 일하라고? 뭐라고?