Wifebeater (shirt)

A sleeveless shirt is a shirt manufactured without sleeves, or one whose sleeves have been cut off. Sleeveless shirts are worn by either sex, depending on the style. They are often used as undershirts, are often worn by athletes in sports such as track and field and triathlon, and are regarded as acceptable public casual dress in most warm weather locales.

The term "A-shirt" is short for "athletic shirt" because it is often worn in sports, such as basketball and track-and-field events. In the United States and Canada, it is commonly known as a tank top and also in the US by the pejorative nicknames wife-beater (sometimes just beater) and guinea tee or dago tee ("guinea" and "dago" being US ethnic slurs for people of Italian ethnicity). In the UK an A-shirt, especially when used as an undershirt, is known as a vest (compare the American usage of "vest"). Another term is singlet, used in England, Scotland, Ireland, Australia, Ghana, Nigeria, Hong Kong, Singapore and New Zealand. In the Philippines, when used as an undershirt it is called a sando. In Bangladesh and the State of West Bengal in India it is called as sando-genji; in other eastern states of India it is called sando-ganji. In India it is known as a banian and is used extensively as an undershirt to absorb sweat and prevent its penetration to outer layers of clothing. In France it is commonly called a "marcel" since its first large-scale production by Marcel Eisenberg for the Parisian handlers during the mid 19th century, or more formerly a "débardeur," meaning "docker," "porter" or "stevedore."

In addition to athletic usage, A-shirts have traditionally been used as undershirts, especially with suits and dress shirts. They are sometimes worn alone without a dress shirt or top shirt during very warm and/or humid weather, mainly in North America where the climate is warmer and more humid in the summer. A-shirts are often worn alone under very casual settings, as lounge wear, and/or while completing yard work or other chores around the home.

...
Wikipedia