The Collaborative International Dictionary of English v.0.48:

Rail \Rail\, n. [F. r[^a]le, fr. r[^a]ler to have a rattling in
   the throat; of German origin, and akin to E. rattle. See
   Rattle, v.] (Zool.)
   Any one of numerous species of limicoline birds of the family
   Rallidae, especially those of the genus Rallus, and of
   closely allied genera. They are prized as game birds.
   [1913 Webster]

   Note: The common European water rail (Rallus aquaticus) is
         called also bilcock, skitty coot, and brook
         runner. The best known American species are the
         clapper rail, or salt-marsh hen (Rallus longirostris,
         var. crepitans); the king, or red-breasted, rail
         (Rallus elegans) (called also fresh-water
         marshhen); the lesser clapper, or Virginia, rail
         (Rallus Virginianus); and the Carolina, or sora, rail
         (Porzana Carolina). See Sora.
         [1913 Webster]

   Land rail (Zool.), the corncrake.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Water rail \Wa"ter rail`\ (Zool.)
   Any one of numerous species of rails of the genus Rallus,
   as the common European species (Rallus aquaticus). See
   Illust. of Rail.
   [1913 Webster]