Gida is an alternate spelling of Gedah.
Hagg is another term for the feller of trees. The Javanese were woodsmen. Other stories with woodsmen include Red Riding Hood. That is ironic since the Javanese origin story involves a girl and a were-creature. Given their profession, it seems more likely that they are descended from the human hunter who was shamed for having tried to kill the were-man/were-god and his female mate.
The Gidyah Tree for Aboriginal people in Australia is known as the Coobarool.ttps://books.google.com/books?id1LqCAAAAIAAJ&pg=PA14&lpg=PA14&dq=gidyah+meaning&source=bl&ots=a-z3njyGO3&sig=ACfU3U2v2lD6k71lVBFvRK7BU8sIvvS72w&hl=en&sa=X&ved=2ahUKEwi7gO2qovD4AhWBIn0KHSf-C_IQ6AF6BAgsEAM#v=onepage&q=gidyah%20meaning&f=false
And, strangely, in Cooba, NSW, there is a town called Reno. There is also a town called Erin Vale. In researching Erin Vale, it leads me back to South Africa-which is where my aunt and uncle lived.