This is the 25th most frequent Korean word.
열린
"열린" means "open" in English.
Here, '열린' describes the noun '마음' metaphorically, emphasizing openness as a mental state.
열린 마음으로 새로운 것을 배우자.
Let's learn new things with an open mind.
In this sentence, '열린' modifies the noun '회의', indicating the meeting was open or accessible to participation.
시간이 겹쳐 있어 열린 회의에 참석하지 못했어요.
I couldn't attend the open meeting because of overlapping schedules.
The word '열린' functions as an adjective modifying the noun '문', to describe that the door was open.