Source : Webster's Revised Unabridged Dictionary (1913)

Red-tailed \Red"-tailed`\ (-t?ld`), a.
   Having a red tail.

   {Red-tailed hawk} (Zo["o]l.), a large North American hawk
      ({Buteo borealis}). When adult its tail is chestnut red.
      Called also {hen hawck}, and {red-tailed buzzard}.