A T-shirt (or tee shirt)'s a shirt which's pulled on over the head to cover most of a person's torso. A T-shirt's usually buttonless, collarless, and pocketless, with a round neck and short sleeves. The sleeves of the T-shirt extend at least slightly over the shoulder but not completely over the elbow (in short-sleeve version). A shirt that's either longer or shorter than this ceases to be a T-shirt. T-shirts are typically made of cotton or polyester fibers (or a mix of the two), knitted togeth… (More on T-shirt)