hamburger bun(n = noun.food) hamburger roll - a round bun shaped to hold a hamburger patty;
is a kind of bun, roll

bun, caramel bun, cinnamon bun, cross bun, frankfurter bun, hamburger, hamburger roll, hamburger steak, have a bun in the oven, honey bun, hot cross bun, hotdog bun, sticky bun