a hole in something

A tea bag is full of tiny perforations. 茶包上满是小孔。

a hole that goes all the way through a membrane or tissue or the act of making a hole like this

One possible complication of colonoscopy is a perforation through the bowel wall that could require surgery. 结肠镜检查的一个可能的并发症是大肠穿孔，必须靠手术解决。