The Collaborative International Dictionary of English v.0.48:

Corncrake \Corn"crake`\ (k[^o]rn"kr[=a]k`), n. (Zool.)
   A bird (Crex crex or Crex pratensis) which frequents
   grain fields; the European crake or land rail; -- called also
   corn bird.
   [1913 Webster]

WordNet (r) 3.0 (2006):

corncrake
    n 1: common Eurasian rail that frequents grain fields [syn:
         corncrake, land rail, Crex crex]