The Collaborative International Dictionary of English v.0.48:

Fishhawk \Fish"hawk`\, n. (Zool.)
   The osprey (Pandion halia["e]tus), found both in Europe and
   America; -- so called because it plunges into the water and
   seizes fishes in its talons. Called also fishing eagle, and
   bald buzzard.
   [1913 Webster]