Other forms: clucking; clucked; clucks
The sound a chicken makes is a cluck. One of the best things about keeping chickens in your yard is watching them scratch the dirt and listening to their clucks.
A chicken or hen clucks when she's rounding up her chicks, making a short, relatively deep sound. To do this is also to cluck, and you can use the word to talk about a fussy or overprotective parent too: "It's so funny watching him cluck over his kids at the playground." The Old English root of cluck is cloccian, and both words are imitative — they echo the sound they're describing.