This is the 1029th most frequent Korean word.
않았던
"않았던" means "did not" or "had not" in past tense, describing something that did not happen or was not done.
Used in a relative clause to describe the movie that was not watched.
어젯밤에 보지 않았던 영화를 오늘 봤습니다.
I watched the movie today that I hadn't seen last night.
Used to indicate a prior action that was negated concerning the opportunity.
그가 주지 않았던 기회를 이제는 잡고 싶습니다.
I now want to seize the opportunity he did not give.
Used to describe a location that was not visited before.