expression, ichidan verb
run out of patience; snap; lose one's temper
Idiomatic expression literally meaning 'the cord of one's patience bag snaps'. Used when someone finally loses their temper after enduring for a long time.
何度も遅刻されて、ついに堪忍袋の緒が切れた。
After being late so many times, I finally ran out of patience.
The boss snapped at his irresponsible attitude.