The word bill has several meanings:

1. A written statement showing money owed for goods or services. When your family eats at a restaurant, the server brings a bill showing what you ordered and the total cost. You might receive a bill for electricity usage, or a doctor might send a bill after your checkup. The phrase “foot the bill” means to pay for something, like when your parents foot the bill for your birthday party.
2. Paper money, like a dollar bill or a twenty-dollar bill. Americans call their currency bills rather than notes. You might have a few dollar bills in your pocket for buying lunch.
3. A proposed law being considered by a legislature. Before something becomes law, it's introduced as a bill in Congress or a state legislature. Representatives debate the bill, sometimes changing it, before voting on whether it should become law.
4. The beak of a bird, especially waterfowl like ducks and geese. A duck's bill is flat and wide, perfect for scooping food from water. A pelican has a huge bill with a pouch underneath for catching fish.

As a verb, bill can mean to send someone a bill or charge them for something: a company might bill a customer for a service.