Cluck

Noun

 * 1) The sound made by a hen, especially when brooding, or calling her chicks.
 * 2) Any sound similar to this.
 * 3) A kind of tongue click used to urge on a horse.

Verb

 * 1) To make such a sound.
 * 2)  to suffer withdrawal from heroin.

Adverbs for Cluck
busily; anxiously; Industriously; maternally; absorbedly; endlessly; cheerfully; fondly; pleasantly; unrestrainedly.

Thesaurus
cackle, call, carol, caw, chatter, cheep, chirk, chirp, chirr, chirrup, chitter, chuck, clack, cock-a-doodle-doo, coo, croak, cronk, crow, cuckoo, dimwit, drum, dumb, gabble, gaggle, gobble, guggle, honk, hoo, hoot, peep, pip, pipe, quack, roll, scold, sing, squawk, trill, tweet, twit, twitter, warble, whistle

Etymology
Onomatopoeic.