The most common Korean word for “key” is 열쇠 (yeolsoe). 「key」는 한국어로 열쇠.
Learn 열쇠 free — flashcards, audio and review →「열쇠」 단어장으로 무료로 외우기Words and levels: TOPIK I essentials (National Institute of Korean Language standard curriculum, KOGL Type 1) · examples: Cheesepotato