Definition of rubby-dubby in English:

rubby-dubby

noun

British
  • Minced fish such as pilchards, mackerel, etc., placed in a net bag and used as a lure for sharks and other large fish.

Origin

1950s. Origin uncertain. Perhaps a reduplication of dub, perhaps suggested by rub-a-dub, rub-a-dub-dub, etc.

Pronunciation

rubby-dubby

/ˈrʌbɪˌdʌbi/