chav (tʃæv)

— n
        informal , derogatory ( Southern English ) a young working-class person whose tastes, although sometimes expensive, are considered vulgar by some


The collins dictionary defines Chav as

"a young working class person who dresses in casual sports clothing".



hmmmm .... not very enlightening on the subject of behaviour ...


But, as with many words, it all depends on who is saying it.