잃어버리다
ireobeorida · TOPIK 1
to lose (completely), to misplace
🔑 잃다 (lose) + 버리다 (throw away) = lose it for good
잃어 is the connective form of 잃다, to lose. 버리다 means to throw away, and as a helper verb it marks an action as fully done, often with regret. So 잃어버리다 is losing something completely, like misplaced keys.