A kind of unraised bread, of many varieties, plain, sweet, or fancy, formed into flat cakes, and bakes hard; as, ship biscuit.
A small loaf or cake of bread, raised and shortened, or made light with soda or baking powder. Usually a number are baked in the same pan, forming a sheet or card.
A small lump of bread, like a deformed roll, made from dough that has been rolled and then cut or else dropped from a spoon. The American usage is inaccurate since "biscuit" means "twice-cooked". What the British correctly refer to as a biscuit is called a "cracker" in the US.