A tee shirt (also spelled T-shirt) is a casual shirt with short sleeves and no collar or buttons, shaped like the letter T when you lay it flat. The name comes from that T shape: the body of the shirt forms the vertical line, and the sleeves stretch out like the horizontal line across the top.

Tee shirts started as undergarments that workers and sailors wore beneath their regular clothes in the early 1900s. By the 1950s, actors like Marlon Brando and James Dean made them fashionable as regular clothing. Today, they're one of the most common pieces of clothing in the world.

People wear tee shirts for comfort, but they've also become a way to express yourself. A shirt might display your favorite band, a funny saying, your school's name, or a cause you care about. Some tee shirts are plain and simple, while others feature colorful designs or messages. Athletes wear them for practice, artists use them as blank canvases, and just about everyone owns at least a few in their dresser drawer.