Digger and Diggers can have a number of different meanings:

Digger

1. Australian and New Zealand slang term for a soldier: Digger (soldier)
2. The name of a computer program: Digger (computer game)
3. An engineering vehicle: Excavator
4. An obsolete derogatory term for the Native Americans of California
5. The Digger Song found under 'Land Rights' on the List of protest songs.

Diggers

1. A democratic utopian group of radicals during the English Civil War: Diggers (True Levellers)
2. An American anarchist movement: Diggers (theater)
3. Diggers, the second book in The Bromeliad trilogy by Terry Pratchett