1a person, animal, or large machine that digs earth.
a person who excavates archaeological sites.
2 (Digger) a member of a group of radical dissenters formed in England in 1649 as an offshoot of the Levellers, believing in a form of agrarian communism in which common land would be made available to the poor.
3Australian/NZ informal a man, especially a private soldier (often used as a friendly form of address):how are you, Digger?
[early 20th century: from digger 'miner', reinforced by association with the digging of trenches on the battlefields]