Source : Webster's Revised Unabridged Dictionary (1913)

Duckbill \Duck"bill`\, n. (Zo["o]l.)
   See {Duck mole}, under {Duck}, n.

Source : WordNet®

duckbill
     n 1: primitive fish of the Mississippi valley having a long
          paddle-shaped snout [syn: {paddlefish}, {Polyodon
          spathula}]
     2: small densely furred aquatic monotreme of Australia and
        Tasmania having a broad bill and tail and webbed feet;
        only species in the family Ornithorhynchidae [syn: {platypus},
         {duckbilled platypus}, {duck-billed platypus}, {Ornithorhynchus
        anatinus}]

duckbill
     adj : having a beak resembling that of a duck; "a duck-billed
           dinosaur" [syn: {duck-billed}]