'Aussie slang'? Is the author Australian and assuming it's regional, or American say and it's not in the vernacular there and assuming it's specifically Austral

'Aussie slang'? Is the author Australian and assuming it's regional, or American say and it's not in the vernacular there and assuming it's specifically Australian? (It's attributed to Urban Dictionary, but not listed there; just with the addition of 'I' which has a different definition not mentioning Australia.)