The phrase "oven door" refers to the hinged panel on the front of an oven that opens and closes. It allows us to put food inside the oven and take it out when it's cooked. Full definition
Place them on greased cookie sheet or parchment paper and bake for 12 minutes and when time goes off, open oven door slightly, turn off oven, and let cookies cool in oven for 20 minutes (keatseats.com)
Expect it to bubble and steam; then close oven door quickly. (mybizzykitchen.com)
125 with oven door open at first notch that it will stay open as to let moisture out. (marthastewart.com)