Source : Webster's Revised Unabridged Dictionary (1913)

Crow \Crow\, n. [AS. cr?we a crow (in sense 1); akin to D.
   kraai, G. kr?e; cf. Icel. kr?ka crow. So named from its cry,
   from AS. cr?wan to crow. See {Crow}, v. i. ]
   1. (Zo["o]l.) A bird, usually black, of the genus {Corvus},
      having a strong conical beak, with projecting bristles. It
      has a harsh, croaking note. See {Caw}.

   Note: The common crow of Europe, or carrion crow, is {C.
         corone}. The common American crow is {C. Americanus}.
         See {Carrion crow}, and Illustr., under {Carrion}.

   2. A bar of iron with a beak, crook, or claw; a bar of iron
      used as a lever; a crowbar.

            Get me an iron crow, and bring it straight Unto my
            cell.                                 --Shak.

   3. The cry of the cock. See {Crow}, v. i., 1.

   4. The mesentery of a beast; -- so called by butchers.

   {Carrion crow}. See under {Carrion}.

   {Crow blackbird} (Zo["o]l.), an American bird ({Quiscalus
      quiscula}); -- called also {purple grackle}.

   {Crow pheasant} (Zo["o]l.), an Indian cuckoo; the common
      coucal. It is believed by the natives to give omens. See
      {Coucal}.

   {Crow shrike} (Zo["o]l.), any bird of the genera
      {Gymnorhina}, {Craticus}, or {Strepera}, mostly from
      Australia.

   {Red-legged crow}. See {Crough}.

   {As the crow flies}, in a direct line.

   {To pick a crow}, {To pluck a crow}, to state and adjust a
      difference or grievance (with any one).

Source : WordNet®

as the crow flies
     adv : by the shortest and most direct route; "it's 10 miles as the
           crow flies"