It's a noun, 'a chav', 'chavs', and also an adjective - people talk about 'chav behaviour' or 'chav insults' and that sort of thing.

它可以是名词a chav——一个chav，或者多个chav。它还可以做形容词，人们会聊到chav behaviour（类似chav的行为）或者chav insults（chav般的粗话）这类的措辞。