To perforate something is to make a hole or holes through it — all the way through, not just a dent. The word is used in three fairly separate places. In medicine it is the ordinary professional word: a bullet perforates the lung, an ulcer perforates the stomach wall, a doctor warns that too much pressure can perforate the eardrum. Doctors here say it in Chinese as 穿孔, and it is serious every time. In manufacturing it means making a neat line of small holes on purpose so that paper can be torn straight — stamps, receipt books, the little tear-off strip on a form; that is where 'perforated' most often appears. In engineering it describes metal or board punched full of holes for air or sound, like the ceiling panels in a classroom. It is a slightly technical, written word: about the toilet paper at home you would say 'tear along the line', not 'perforate'. The related noun is 'perforation', which can mean either the hole itself or the line of holes.

穿孔、打孔（醫學上的「穿孔」如胃穿孔、耳膜穿孔；紙張上是打虛線孔）