migaloo
The Macquarie Dictionary will tell you that migaloo is "Aboriginal English: a white person. Australian Aboriginal: Biri (a language of the Mackay region) migulu: ghost, spirit)." As such, it might be interchangeable with many synonyms across the continent. I might, perhaps, have used balanda if the subject matter concerned the Top End, gubba if the focus was further south, or whitefella if the text was going to include blackfella. However, my initial exposure to Indigenous English was to murri and migaloo, so that's what I'm sticking with.
