(American) a person who lives in a remote location that is far away from civilization, such as in the woods or on the border or developed/settled and undeveloped/unsettled land;
e.g. He had been a bushranger for most of his life, and he was nervous to move to a town.
(noun)
(Australian, historical) a person who is a fugitive from the law living i8n the wilderness (the bush);
e.g. They thought the person might be a bushranger, but they were too far away to be certain.