The dunny was originally any outside toilet. In cities and towns the pan type dunny was emptied by the dunny man, who came around regularly with his dunny cart.
Dunny can now be used for any toilet.
The word comes from British dialect...dunnekin...meaning an
"earth closet, (outside) privy" from dung + ken "house".
First recorded in the 1930s but dunnekin is attested in Australian sources from the 1840s.
1957 Overland x....
We used ter have a snake in the dunny - lav, sir
2000 Tracks, January...
The scourge of the summer festival-goer has to be the crusty dunnies.