Source : Webster's Revised Unabridged Dictionary (1913)

Openbill \O"pen*bill`\, n. (Zo["o]l.)
   A bird of the genus {Anastomus}, allied to the stork; -- so
   called because the two parts of the bill touch only at the
   base and tip. One species inhabits India, another Africa.
   Called also {open-beak}. See Illust.
   (m), under {Beak}.

Source : WordNet®

openbill
     n : stork with a grooved bill whose upper and lower parts touch
         only at the base and tip