TextileGlossary.com

A vest is a type of men's garment. The term has different meanings in the United Kingdom and the United States. In the UK, a vest is an undergarment typically taking the form of a white sleeveless T-shirt. When worn without anything on top, it may be jocularly referred to as a wifebeater, due to the stereotype of violent men as people who sit around in their underwear drinking beer.
A variant is the string vest which is constucted from a loosely woven string mesh. The string vest in particular is seen as having comic potential and is even more strongly associated older aged working class men.
A vest may also be worn as an outer garment in sports wear, especially in athletics. Advanced sports vests are made from hitech man-made materials designed to wick persperation away from the body and aid cooling.
In the US, the word vest is used to mean refer to what is referred to as a waistcoat in the UK. What the UK refers to as vests are called "undershirts" in the US. However, most undershirts in the US have sleeves and resemble T-shirts. In this context, the vest is commonly associated with outdoor activities. The padded vest is popular apparel for hunting. Another common variant is the fishing vest which carries a profusion of external pockets for carrying fishing tackle

A vest is worn in place of a cummerbund to cover the waistband. A vest is usually worn with a coordinating bow tie. A vest comes in a full back, half back and open back.