Green’s Dictionary of Slang

1. (N.Z.) New Zealand.

1916		ANZAC Book vi: [cap. title] Diggerland.
1918		N.Z. at the Front 77: [title] Diggerland.

2. Australia.

1926

Dly Herald 15 Oct. 5/6: Now Billy Hughes was a Prime Minister [...] the most caricatured man in Diggerland [...] the Australian Press was on his side. Even the dear old Bulletin was, but the ‘Bully’ has changed its politics lately.