An item of casual clothing: a top with no sleeves.
The top of a ship's bilge tank, usually the lowest horizontal surface on board.
Alternative forms
tanktop
tank-top
Noun
tank top (plural tank tops)
Nickname for alcoholic drinks reputed to arouse pugnacity: Rum, called "the golden wifebeater", Stella Artois, sometimes called "Wife Beater" in the UK (http://en.wikipedia.org/wiki/Wife-beater).
A wife-beater is commonly viewed as a skinny, tank-styled, ribbed shirt. They come in all sizes and colors and are usually worn underneath another shirt but they can also be worn by themselves. The iconic shirt has been worn by men, but currently women too can wear a variation of it which may be called a “boy-beater” even a young child may now wear a “lil-wife beater.” In recent years there has been a major resurgence of the wife-beater. Even popular designers such as Gap and Dolce and Gabbana have put their own twist on the shirt by adding jewels and accessories, making it into a stylish every day look.
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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 also known colloquially as a tank top or by its pejorative nicknames, wife-beater (sometimes just beater), or guinea tee (which come from the cultural stereotype where they are considered an underwear-only type of clothing and wearing one in public is alleged to connote low social class; guinea is an ethnic slur for an Italian). 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, Nigeria, Singapore and New Zealand. In the Philippines, when used as an undershirt it is called a sando. Also 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 Northern and Central 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 Parisians handlers during the mid 19th century.
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.
The build of an A-shirt 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. They are also sometimes made long to make tucking into a pair of jeans/shorts easier. In almost all cases, they are buttonless, collarless, and pocketless. An A-shirt worn as an undershirt is designed for a tight fit and is often made of ribbed cotton.
A tank top consists of a sleeveless shirt with low neck and different shoulder straps width. It is named after tank suits, one-piece bathing costumes of the 1920s worn in tanks or swimming pools. The upper garment is worn commonly by both men and women (http://en.wikipedia.org/wiki/Sleeveless_shirt).