A sleeveless shirt is a shirt that is manufactured without sleeves or whose sleeves have been cut off. Depending on the style, they can be worn as undershirts, by athletes in sports such as track and field and triathlon, or as casual wear by both men and women alike. Tank top In the United States and Canada, any casual sleeveless shirt can be called tank top or tank shirt, with several specific varieties. It is named after tank suits, one-piece bathing suits of the 1920s worn in tanks or swimming pools. The upper garment is worn commonly by both men and women. The build of a tank top is simple: the neck and armholes are often reinforced for durability. One usually has large armholes and neck holes and a neckline that can reach down as far as the bottom of the chest. (Women's tank tops have smaller holes, to conceal their breasts). They are also sometimes made long to make tucking into pants easier. In almost all cases, they are buttonless, collarless, and pocketless. A sleeveless T-shirt, also called a muscle shirt, is the same design as a T-shirt, but without sleeves. Some sleeveless T-shirts, which possess smaller, narrower arm holes, are traditionally worn by both women and men. They are often worn during athletic activities or as casual wear during warmer weather. They are colloquially known as shooter shirts in the southern United States. They were quite popular in the 1980s and were commonly associated with surfers and bodybuilders (hence the name "muscle" shirt) and often bore the names and logos of gyms. Such shirts without logos are now more commonly worn as casual wear. The tank top designed for a tight fit and often made of ribbed cotton is also called a wifebeater, beater, or A-shirt, or historically a guinea tee, or dago tee (guinea and dago being American ethnic slurs for people of Italian ethnicity). The term wife-beater reportedly became synonymous for an undershirt after a 1947 criminal case where a Detroit man was arrested for beating his wife to death, and newspapers printed a photo of the "wife beater" wearing a stained undershirt. Another claim was spread by Paul Davidson, a film-maker, in a blog post where he claimed that the term had evolved from a medieval chain mail undergarment called a "waif-beater," and this was picked up as fact by other outlets. Davidson openly admitted