bun

A bun is a small, rounded bread product typically served as a bread roll or sandwich base. In baking, buns are usually made from yeast-leavened dough enriched with fat, milk, sugar, or eggs, yielding a tender crumb. They are distinct from larger loaves and from everyday flat breads, though regional terminology varies.

Doughs for buns are prepared by mixing flour, water or milk, yeast, salt, and optional sugar and fat. After mixing, the dough is kneaded and allowed to rise (proof) before being divided, shaped, and baked until golden. Some buns are steamed rather than baked, yielding a soft, moist texture. Buns can be sweet or savory, and many cultures use them for sandwiches or as desserts. Common varieties include plain dinner rolls, hamburger buns, hot dog buns, brioche buns, and sweet rolls such as cinnamon buns and currant buns. In East Asia, steamed buns such as bao or mantou are a major category, and are often filled or glazed.

Regional forms vary in density, sweetness, and size. In the modern food industry, buns are widely produced commercially, enabling mass-market hamburger buns and packaged sweet rolls.

Beyond food, bun denotes a hairstyle in which hair is drawn into a knot or coil at the back of the head. The term is also used in phrases like "bun in the oven" to refer to pregnancy.