Source : Webster's Revised Unabridged Dictionary (1913)

Cluck \Cluck\, v. i. [imp. & p. p. {Clucked}; p pr. & vb. n.
   {Clucking}.] [AS. cloccian; cf. D. klokken, G. glucken,
   glucksen, LG. klukken, Dan. klukke; all prob. of imitative
   origin.]
   To make the noise, or utter the call, of a brooding hen.
   --Ray.

Cluck \Cluck\, v. t.
   To call together, or call to follow, as a hen does her
   chickens.

         She, poor hen, fond of no second brood, Has clucked
         three to the wars.                       --Shak.

Cluck \Cluck\, n.
   1. The call of a hen to her chickens.

   2. A click. See 3d {Click}, 2.

Source : WordNet®

cluck
     n : the sound made by a hen (as in calling her chicks)
     v : make a clucking sounds, characteristic of hens [syn: {click},
          {clack}]