The Collaborative International Dictionary of English v.0.48:

Boatbill \Boat"bill`\, n. (Zool.)
   1. A wading bird (Cancroma cochlearia) of the tropical
      parts of South America. Its bill is somewhat like a boat
      with the keel uppermost.
      [1913 Webster]

   2. A perching bird of India, of the genus Eurylaimus.
      [1913 Webster]

WordNet (r) 3.0 (2006):

boatbill
    n 1: tropical American heron related to night herons [syn:
         boatbill, boat-billed heron, broadbill, Cochlearius
         cochlearius]