cluck vs clack

cluck and clack both are nouns.

Word	Noun	Adjective	Verb	Adverb
cluck	Yes	No	Yes	No
clack	Yes	No	Yes	No

As verbs, cluck and clack are synonyms defined as:

Other synonyms of cluck include click.

cluck (noun)	clack (noun)
the sound made by a hen (as in calling her chicks)	a simple valve with a hinge on one side; allows fluid to flow in only one direction
	a sharp abrupt noise as if two objects hit together; may be repeated

cluck (verb)	clack (verb)
make a clucking sounds, characteristic of hens	speak (about unimportant matters) rapidly and incessantly
	make a clucking sounds, characteristic of hens
	make a rattling sound