A vest, undershirt, tank top, , singlet (Brit.) or a wife beater is an article of underwear worn underneath a dress shirt

Shirt

A shirt is a cloth garment for the upper body. Originally an undergarment worn exclusively by men, it has become, in American English, a catch-all term for almost any garment other than outerwear such as sweaters, coats, jackets, or undergarments such as bras, vests or base layers...

 intended to protect them from body sweat and odors. It can have short sleeves or be sleeveless. The term most commonly refers to upper-body wear worn by males.

It also makes dress shirts less transparent

Transparency and translucency

In the field of optics, transparency is the physical property of allowing light to pass through a material; translucency only allows light to pass through diffusely. The opposite property is opacity...

. It can also be worn during winter months as an extra layer of warmth.

History

Factory mass produced undershirts became common in the West in the early 20th century, with innovations turning the union suit

Union suit

A union suit is a type of one-piece long underwear. Created in Utica, New York, United States, it originated as women's wear during the 19th-century United States clothing reform efforts, as an alternative to constricting garments, and soon gained popularity among men as well...

 into two pieces, for upper and lower body.

Types of undershirts

• A-shirt
• T-shirt
  T-shirt
  A T-shirt is a style of shirt. A T-shirt is buttonless and collarless, with short sleeves and frequently a round neck line....