Biscuit

Biscuit is a small cake of bread made of flour of wheat, maize, corn, barley or other foodgrains. It is baked with baking powder, baking soda, or yeast, leavened in small sizes, soft, and typically in round shape.

Cookies or crackers of a light brown colour are also called biscuits. These are flat, dry, small, and crispy. It is also baked of flour of foodgrains or corn, typically in round shape. Biscuits in various shapes and sizes are also baked with added sugar or salt but without yeast or raising agents.

By analogy, a small flat piece of something is also called biscuit, such as biscuit of gold, plastic, or wood.