Definition of blue duck in English:

blue duck

noun

  • 1A rare duck, Hymenolaimus malacorhynchos, of swiftly flowing mountain streams in New Zealand, which has blue-grey plumage.

  • 2NZ Australian
    slang Australian and NZslang. A lost cause, a failure. Compare earlier dead duck.

Origin

Mid 19th century. From blue + duck.

Pronunciation

blue duck

/bluː ˈdʌk/