WATER-Pad,
one that robs Ships, Hoys, Lighters, Barges or Boats in the River of Thames. A sort of BADGERS. Which see.
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Entry taken from 1736 Canting Dictionary, by Nathan Bailey.
The Vulgar Tongue originally collected by Grose, 1811.
Also see examples in Canting Songs and Slang Rhymes collected by John S. Farmer (1896).