[q=oddler or whatever]Edit: fast food
–noun food, as hamburgers, pizza, or fried chicken, that is prepared in quantity by a standardized method and can be dispensed quickly at inexpensive restaurants for eating there or elsewhere.[/q]

I can go to a sit-down restaurant and get food that is prepared in quantity by a standardized method inexpensively for eating there or elsewhere. The key factor is time. Any time you order a pizza from any pizza place, it's prepared fresh, and thus will take at least ten, usually closer to fifteen minutes to cook and become ready for eating. However, at a place such as Burger King, food is constantly being made, and is received by the customer within a couple minutes typically. Hence, pizza from Domino's or Pizza Hut can take up to 10 times longer to receive (even more for real pizza restaurants) than a bacondoublecheeseburgerholdthepickles from Burger King.

As for frozen pizzas, the term "fast food" refers not to food cooked at home (would you call toast "fast food"?), but to that cooked in restaurants and purchased for personal consumption after cooking. So frozen pizzas are microwaved foods, not fast food.