Placket – an opening or slit in a garment, covering fastenings or for access to a pocket, or the flap of fabric under such an opening.

“I rubbed my hand against the placket of my trousers.”

It’s such a specific thing to have a word for – an opening which covers fastenings. I can’t help wondering who thought it was a good plan to create such a word. Don’t get me wrong – I’m not complaining. I think it’s rather splendid. But I also think it’s odd.