마음을 놓아요(놔요) · 마음을 놓았어요 · 마음 놓고 (without worry)
to relax, to stop worrying, to feel at ease
Example
아이가 무사히 도착했다는 전화를 받고 마음을 놓았어요.
I got a call that my child had arrived safely, and I could finally relax.
Word parts
Literally 'to put down one's heart,' like setting down a heavy load.