Pommy or Pom
The term pommy, pom or pommie, in Australia, New Zealand and South Africa usually denotes a person of mainly English heritage or origin, less commonly British in general. It was ruled not offensive in 2006 by the Australian Advertising Standards Board and in 2010 by the New Zealand Broadcasting Standards Authority. The community group British People Against Racial Discrimination were among those who complained to the Advertising Standards Board about five advertisements poking fun at "Poms", prompting the 2006 decision.
There are several folk etymologies for "Pom," some of which are false etymologies. For example, there are rumors that the word's etymology is related to prisoners, such as "Prisoner of Millbank," but this claim is suspect. A more likely theory is that pommy originated as a contraction of "pomegranate". According to this explanation, "pomegranate" is extinct Australian rhyming slang for immigrant. A popular alternative explanation for the theory that pommy is a contraction of "pomegranate", relates to the purported frequency of sunburn among British people in Australia, turning their fair skin the colour of pomegranates. However, there is no hard evidence for the theory regarding sunburn. Another false explanation was that it derived from acronyms such as P.O.M.E. for Prisoner of Mother England and P.O.H.M.S. Prisoner Of Her Majesty's Service. However, there is no evidence that these terms, or their acronyms, existed. An alternative origin of the term is that it derives from the word "pompous".
http://en.wikipedia.org/wiki/Alternative_names_for_the_British