Source : Webster's Revised Unabridged Dictionary (1913)

Hawk \Hawk\, n. [OE. hauk (prob. fr. Icel.), havek, AS. hafoc,
   heafoc; akin to D. havik, OHG. habuh, G. habicht, Icel.
   haukr, Sw. h["o]k, Dan. h["o]g, prob. from the root of E.
   heave.] (Zo["o]l.)
   One of numerous species and genera of rapacious birds of the
   family {Falconid[ae]}. 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.

   Note: Among the common American species are the red-tailed
         hawk ({Buteo borealis}); the red-shouldered ({B.
         lineatus}); the broad-winged ({B. Pennsylvanicus}); the
         rough-legged ({Archibuteo lagopus}); the sharp-shinned
         {Accipiter fuscus}). See {Fishhawk}, {Goshawk}, {Marsh
         hawk}, under {Marsh}, {Night hawk}, under {Night}.

   {Bee hawk} (Zo["o]l.), the honey buzzard.

   {Eagle hawk}. See under {Eagle}.

   {Hawk eagle} (Zo["o]l.), an Asiatic bird of the genus
      {Spiz[ae]tus}, or {Limn[ae]tus}, intermediate between the
      hawks and eagles. There are several species.

   {Hawk fly} (Zo["o]l.), a voracious fly of the family
      {Asilid[ae]}. See {Hornet fly}, under {Hornet}.

   {Hawk moth}. (Zo["o]l.) See {Hawk moth}, in the Vocabulary.
      

   {Hawk owl}. (Zo["o]l.)
   (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.