Mid 19th century. Origin uncertain. Apparently related to later charver
1990s; earliest use found in Usenet (newsgroups). From Angloromani chava man, child, boy from Romani čhavo
late 19th century. Origin uncertain. Compare earlier charver, which is apparently related, and from which the verb could be derived, although most have assumed that the opposite is the case (in spite of the chronology of the first attestations, which may well be accidental). Both words have been identified as part of Polari slang (compare I. Hancock Shelta and Polari in P. Trudgill (ed.) Language in the British Isles (2003) 384–403), although they may not have originated as part of it.

• chav from [1990s]:

  Baseball cap, fake designer sportswear, cheap jewellery—that is the uniform of the chav, a loutish, obnoxious youth who barged his way into the British consciousness in 2004. Popularized by websites and the tabloid press, the term caught on quickly, and soon women and older people too were being described as chavs. New words appear all the time, but chav caused great excitement to word scholars when it came on the scene. It seems to have been popular around Chatham in Kent during the late 1990s, and some people think that it is an abbreviation of the town's name, while others suggest it comes from the initial letters of ‘Council House And Violent’. The most plausible suggestion is that it is from the Romany word chavi or chavo, ‘boy, youth’. The related dialect word chavvy ‘boy, child’ was used in the 19th century and is still occasionally in use. The northeast variant of chav, charver, has been around since at least the 1960s, and chav can mean ‘mate, pal’ in Scots dialect. Chav was probably knocking around as an underground expression for a long time before it was taken up as a new way of insulting people.