청강이 · 청강을
auditing (a class), sitting in on a lecture
Example
다른 학과 수업을 청강해도 될까요?
May I audit a class in another department?
Word parts
청 listen+강 lecture
Literally 'listening to a lecture'.
Good to know
수강 means officially taking a course for credit; 청강 means sitting in without credit.
Related words