술술 + 풀리다 / 읽히다 / 나오다
smoothly, easily, fluently
Example
오늘 시험 문제가 술술 잘 풀렸어요.
The test questions went really smoothly for me today.
Word parts
Mimetic of a smooth flow, like thread unspooling or water running.
Good to know
Common in 일이 술술 풀리다 'things go smoothly' and 술술 읽히다 'an easy read'.