If your patience wears thin, you become less and less patient.

I've warned you several times about being late and my patience is wearing thin. 我多次警告你不要迟到，我对你已经失去耐心了。

If something such as a joke wears thin, it becomes boring or annoying or stops being funny or effective, because it has been seen, heard, or used too much.

Tony, the joke is beginning to wear thin now - it's time to stop. 托尼，那个笑话现在已经变得不那么好笑了——别再讲了。

Her standard excuse for being late was beginning to wear thin. 她迟到时常用的那个借口已经开始不太管用了。