Merriam-Webster's Collegiate® Dictionary, 11th Edition
CLUCK
I. verb
Etymology: imitative
Date: 15th century
intransitive verb to make a cluck, to make a clicking sound with the tongue, to express interest or concern , transitive verb to call with a cluck, to express with interest or concern,
II. noun
Date: 1703
the characteristic sound made by a hen especially in calling her chicks, a stupid or naive person