A) A derogatory slang term to mean any type of gypsy, synonymous to "gypo". (This is the original meaning, though it is now far less common).
B) A member of society that is BELOW WORKING CLASS as they usually live by benefits, in council housing and do not hold employment. One of many localised terms for the same people that has now become popularly labelled as "chavs". They are the absolute dregs of modern society; they contribute nothing and take as much as they can. It is a common misconception that all working class are pikies, this is not the case.
These are usually the descendants of gypsies, so there are many similarities between the 2 definitions, including jewellery such as large medallions, sovereign rings and large hoop earrings; as well as disregard for the law of the land, overwhelming cowardice and lack of any form of morality.
Synonyms include, "townie" (modern meaning), "chav", "scally", "NED", etc. For a detailed description, research any of these terms.
"Travellers", i.e. people who chose to live in caravans to avoid paying tax may or may not be covered by definition (A), but this is rarely an issue as they are usually covered by definition (B).
The antonym to "townie" (traditional meaning; anyone who lives in an urban/suburban location) is "bumpkin" (anyone who lives in a rural environment), not "pikie".
Some pikie started on me the other day; all bark, no bite, that lot, bloody dolescum cowards.
Pikie:- Yes, I'm an Irish Gypsy, thats why we live in mansions and you live on council estates. SO run back to your mamma you prebuscent gerbil-like townie.
However, everywhere else in England. Pikie means practically the same as townie......
etc etc etc