Perforated describes something that has a hole or holes made through it. Almost always it means the holes are deliberate and regular: perforated paper (the dotted line of tiny holes so you can tear a page out cleanly), perforated metal sheets, perforated ceiling tiles that soak up noise, perforated leather in a car seat so your back does not sweat. In a shop or a catalogue this is a plain, useful word. But it is also the standard medical word for damage: a perforated eardrum after a slap or a dive, a perforated ulcer, a perforated bowel — all of which mean a hole where there should not be one, and all of which are emergencies. So the same word is either a design feature or a diagnosis, and only the noun after it tells you which. Note that although it looks like a past participle of 'perforate', people use it far more as a straightforward adjective; you can even say 'more perforated' about a sheet with more holes, though that is rare.