Chav is a term applied to certain young people in the United Kingdom. The stereotypical "chav" is an aggressive teenager, typically unemployed or of working class background, who repeatedly engages in anti-social behaviour, such as street drinking, drug abuse and rowdiness, or other forms of juvenile delinquency. "Chavs" stereotypically wear tracksuits and hoodies made by "name" brands such as Nike, Reebok, Burberry, Helly Hansen and Adidas.
source: wikipedia