Australian slang term for an outdoor dunny. Is generally considered to be a wooden structure about the size and shape of a large phone box, with a pitched roof and a heart-shaped cutout on the door. No connection to sewerage, just a long, vertical pit dug beneath the seat, termed, appropriately enough, a 'longdrop'.

On a side note: The time it takes you to say 'longdrop' is about the time it takes before you hear the 'thud'. Or should that be 'splud'?