"Digger" is an appellation applied to the Australian soldier. According to the Australian Defence Department, its actual origin has been lost in time, although some believe it came about because former gold miners (diggers) were in the early Australian army.
Trench digging activities of the Australian soldiers during World War I may also have given rise to the term.
Originally used in respect of the Australian soldier in World War I, particularly the Anzacs, the term "digger" is now taken to apply loosely and colloquially to any Australian soldier of any era.

