cluck 1
/kluk/ , v.i.
1. to utter the cry of a hen brooding or calling her chicks.
2. to make a similar sound; express concern, approval, etc., by such a sound.
v.t.
3. to call or utter by clucking.
n.
4. the sound uttered by a hen when brooding, or in calling her chicks.
5. any clucking sound.
[ 1475-85; var. of CLOCK (now dial. and Scot), ME clokken, OE cloccian to cluck; c. D klokken ]
cluck 2
/kluk/ , n. Slang.
a dull-witted, stupid person; blockhead; dolt.
[ 1900-05, Amer.; special use of CLUCK 1 ]