Source : Webster's Revised Unabridged Dictionary (1913)

Daker hen \Da"ker hen`\ [Perh. fr. W. crecial the daker hen;
   crec a sharp noise (creg harsh, hoarse, crechian to scream) +
   iar hen; or cf. D. duiken to dive, plunge.] (Zo["o]l.)
   The corncrake or land rail.