Cobra put the finger on the ethnicity aspect with
so to be English is in fact to be a descendant from any/ all of the following - Angle Jute Pict Celt Hun Norman Saxon Roman Viking and latterly Polish Romanian Indo-Chinese Arabic African Afro-Caribbean etc etc etc

But that description also applies to many who were born in Oz (and, I dare say, many other parts of the Commonwealth and even the US) who would never call themselves "English".

When Guest Dazbo asked
why is spin on a pool ball (or baseballs) called english? Peace wrote an excellent answer which included Visitors from England showed Americans how use spin, which explains why it is called "English" in the United States but nowhere else.

But it's called "English" in Oz, possibly because of Walter Lindrum but it probably predated him.

Cheers, Rowan