Coffyn
A coffyn is the medieval English name for a thick, free-standing pastry case that served as both cooking vessel and storage container for a pie's filling.
The walls were made deliberately sturdy, from flour, water, and sometimes fat, so the case could survive hours in a wood-fired oven and seal its contents afterward. The crust was rarely eaten; it was packaging.
The word is the same one that became coffin, and both come from a term for a box or basket. English recipe collections from around 1390 already assume the reader knows how to raise one.