the limit of one's patience; the last straw
Used when someone can no longer endure a situation. Often appears in phrases like 我慢の限界に達する or 我慢の限界を超える.
I finally reached the limit of my patience with his irresponsible attitude.
The constant noise is the last straw.
Compound of 我慢 (patience, endurance) + の (possessive particle) + 限界 (limit). The phrase literally means 'the limit of patience'.