[1] : The Collaborative International Dictionary of English v.0.48

hawk \hawk\ haddk, n. oe. hauk prob. fr. icel., havek,
   as. hafoc, heafoc; akin to d. havik, ohg. habuh, g. habicht,
   icel. haukr, sw. h"ok, dan. h"og, prob. from the root of
   e. heave. zool.
   one of numerous species and genera of rapacious birds of the
   family falconidae. they differ from the true falcons in
   lacking the prominent tooth and notch of the bill, and in
   having shorter and less pointed wings. many are of large size
   and grade into the eagles. some, as the goshawk, were
   formerly trained like falcons. in a more general sense the
   word is not infrequently applied, also, to true falcons, as
   the sparrow hawk, pigeon hawk, duck hawk, and prairie hawk.
   1913 webster

   note: among the common american species are the red-tailed
         hawk buteo borealis; the red-shouldered buteo
         lineatus; the broad-winged buteo pennsylvanicus;
         the rough-legged archibuteo lagopus; the
         sharp-shinned accipiter fuscus. see fishhawk,
         goshawk, marsh hawk, under marsh, night hawk,
         under night.
         1913 webster

   bee hawk zool., the honey buzzard.

   eagle hawk. see under eagle.

   hawk eagle zool., an asiatic bird of the genus
      spizaetus, or limnaetus, intermediate between the
      hawks and eagles. there are several species.

   hawk fly zool., a voracious fly of the family
      asilidae. see hornet fly, under hornet.

   hawk moth. zool. see hawk moth, in the vocabulary.

   hawk owl. zool.
   a a northern owl surnia ulula of europe and america. it
       flies by day, and in some respects resembles the hawks.
   b an owl of india ninox scutellatus.

   hawk's bill horology, the pawl for the rack, in the
      striking mechanism of a clock.
      1913 webster
see also:
falconidae buteo borealis buteo lineatus buteo pennsylvanicus archibuteo lagopus accipiter fuscus 
fishhawk goshawk marsh hawk marsh night hawk 
night bee hawk eagle hawk eagle hawk eagle 
spizaetus limnaetus hawk fly asilidae hornet fly 
hornet hawk moth hawk owl surnia ulula ninox scutellatus 
hawk's bill 

[2] : WordNet (r) 2.0

surnia ulula
     n : gray-and-white diurnal hawk-like owl of northern parts of
         the northern hemisphere syn: hawk owl
see also:
hawk owl 

Ulula >> U Words
Ulula, definition of term: Ulula
ulula_pag1.html

Surnia >> S Words
Surnia, definition of term: Surnia
surnia_pag1.html