A covered building used chiefly for storing grain, hay, and other productions of a farm. In the United States a part of the barn is often used for stables.
- A large farm building used for storing farm products and sheltering livestock.
- A large shed for the housing of vehicles, such as railroad cars.
- A particularly large, typically bare building: lived in a barn of a country house.
- Physics A unit of area equal to 10-24 square centimeters, used to measure cross sections in nuclear physics.