Having some resemblance to an Australian
Partly or to some degree or partially similar to an Australian
Foreigners, tourists, immigrants and those who feel themselves to be Aussies but do not totally fit the criteria e.g. those who refuse to eat Vegemite or beetroot on their burgers, or drink beer, or don't understand what "bringing a plate" means, or what lamingtons are, or an Esky is, or watch the footy, or mow the lawn in thongs are only quasi Aussies, not fair dinkum Aussies.
My husband might be an Australian citizen, and might have lived in Australia for the last 20 years, but he is still a Quaussie. He refuses to eat Vegemite sandwiches, or a burger with beetroot on it and still thinks when the football is advertised he will be able to watch a soccer match!