tuckerbox, n. — Green’s Dictionary of Slang

tuckerbox n.

[Jack Moses poem (c.1920s) ‘The dog sat on the tuckerbox/Nine miles from Gundagai’, usu. recited as ‘shat on...’ thus the derog. term]

1. (Aus.) the stomach.

1901		Sydney Sportsman (Surry Hills, NSW) 3 July 2/7: King landed a beauty just above Ross’ tucker-box.
1921		(con. WWI) E. Lynch Somme Mud 213: A bayonet in a full tuckerbox is dangerous.

2. an informer.

1984

Partridge DSUE (8th edn) 1270–71: [...] early 1970s.