Source : Webster's Revised Unabridged Dictionary (1913)

Corncrake \Corn"crake`\ (-kr?k`), n. (Zo["o]l.)
   A bird ({Crex crex} or {C. pratensis}) which frequents grain
   fields; the European crake or land rail; -- called also {corn
   bird}.

Source : WordNet®

Crex crex
     n : common Eurasian rail that frequents grain fields [syn: {corncrake},
          {land rail}]