Copper; items made of copper

Valuables retrieved from sewers and drains

Rubbish, trash, especially in the sense of nonsense, bosh, balderdash

To steal copper, particularly from ship hulls

“1867, W. H. Smyth, Sailor's Word-book”

To search for valuables in sewers

To use a tosh-pan, either to wash, to splash, or to "bath"