The Collaborative International Dictionary of English v.0.48:
Snakebird \Snake"bird`\, n. [So named from its snakelike neck.]
1. Any one of four species of aquatic birds of the genus
Anhinga or Plotus. They are allied to the gannets and
cormorants, but have very long, slender, flexible necks,
and sharp bills.
Note: The American species (Anhinga anhinga syn. Plotus
anhinga) inhabits the Southern United States and
tropical America; -- called also darter, and water
turkey. The Asiatic species (Anhinga melanogaster)
is native of Southern Asia and the East Indies. Two
other species inhabit Africa and Australia
2. (Zool.) The wryneck.