Grellmann (1787) collected the forms
Tʃchabo Tʃchawo meaning a child and a
boy or son respectively from Continental
gipsies. Smart & Crofton (1875) collected
the forms Chábi ‘a child’ plural chávi
‘children’; Chabo ‘a baby’ from English
Gypsies.
This is the origin of the modern derogatory
term for a ‘a loutish person who
wears designer clothes and is of low social
status’.
Sense 1 with the form chavy attested by Canadian Paul Pope 2013.