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.

Hawk moth \Hawk" moth`\ (?; 115). (Zo["o]l.)
   Any moth of the family {Sphingid[ae]}, of which there are
   numerous genera and species. They are large, handsome moths,
   which fly mostly at twilight and hover about flowers like a
   humming bird, sucking the honey by means of a long, slender
   proboscis. The larv[ae] are large, hairless caterpillars
   ornamented with green and other bright colors, and often with
   a caudal spine. See {Sphinx}, also {Tobacco worm}, and
   {Tomato worm}. Tobacco Hawk Moth ({Macrosila Carolina}), and
   its Larva, the Tobacco Worm.

   Note: The larv[ae] of several species of hawk moths feed on
         grapevines. The elm-tree hawk moth is {Ceratomia
         Amyntor}.

Source : WordNet®

hawk moth
     n : any of various moths with long narrow forewings capable of
         powerful flight and hovering over flowers to feed [syn: {hawkmoth},
          {sphingid}, {sphinx moth}, {hummingbird moth}]