Why is cottage pie called pie?

Cottage pie is not called pie because it contains pastry. The traditional English dish does not have a pastry crust, like a traditional fruit or meat pie. It is simply named "pie" because of its similarity to the more traditional pies. The meat and vegetable filling is covered with a layer of mashed potatoes, which bakes and browns and gives it a "crust" similar to a pie. The "cottage" in the name is most likely a reference to the inexpensive and humble ingredients that were traditionally used to make the dish, which would have been common in rural cottages.