Source : Webster's Revised Unabridged Dictionary (1913)

Pygarg \Py"garg\, Pygargus \Py*gar"gus\, [L. pygargus, Gr. ?,
   literally, white rump; ? the rump + white: cf. F. pygargue.]
   1. (Zo["o]l.) A quadruped, probably the addax, an antelope
      having a white rump. --Deut. xiv. 5.

   2. (Zo["o]l.)
      (a) The female of the hen harrier.
      (b) The sea eagle.