в словарях слово уже зафиксировано:)
chav n. [< chavi, a 19th century Romany word for "child". Note: reported by The Guardian newspaper, 19/10/04. In the far North of England and parts of Southern Scotland it has long been around as a regionalism. It has recently become hip all over Britain. It was chosen as Buzzword of the Year 2004.] A young man wearing cheap gold jewellery and baseball caps and hanging around in shopping centres all over Britain.
(http://www.langmaker.com/db/Eng_chav.htm)