A T-shirt (also spelled tee-shirt or tee shirt), or tee for short, is a style of fabric shirt named after the T shape of its body and sleeves. Traditionally, it has short sleeves and a round neckline, known as a crew neck, which lacks a collar. T-shirts are generally made of a stretchy, light, and inexpensive fabric and are easy to clean. The T-shirt evolved from undergarments used in the 19th century and, in the mid-20th century, transitioned from undergarment to general-use casual clothing.
Originally an undergarment worn exclusively by men, it has become, in American English, a catch-all term for a broad variety of upper-body garments and undergarments. In British English, a shirt is more specifically a garment with a collar, sleeves with cuffs, and a full vertical opening with buttons or snaps (North Americans would call that a “dress shirt”, a specific type of collared shirt). A shirt can also be worn with a necktie under the shirt collar.