To become less convincing, acceptable, or popular, as through repeated use: excuses that are wearing thin.

What does it mean to be worn thin?

1. Be weakened or diminished gradually, as in My patience is wearing thin. [ Late 1800s] 2. Become less convincing, acceptable, or popular, as in His excuses are wearing thin.

Is running thin?

: to become less than the usual, original, or needed number or amount I'd been waiting almost an hour, and my patience was running thin.