Thieves’ Cant. A Thames thief who purloins copper sheathing from the bottoms of vessels in the river or from the docks. So Toshing, the practice of a ‘tosher.’
1859. Slang Dict., Toshers, men who steal copper from ships’ bottoms in the Thames.
1867. Smyth, Sailor’s Word-bk., Toshing, a cant word for stealing copper sheathing from vessels’ bottoms, or from dock-yard stores.
