Longman Dictionary of Contemporary English - cluck

~1 v 1 if a chicken clucks, it makes a short, low sound 2 to express sympathy or disapproval by saying something, or by making a short low noise with your tongue + over/around/abou  (The women stood together clucking over her scandalously short skirt.) - clucking adj ~2 n C usually singular 1 a low short noise made by hens 2 a sound made with your tongue, used to show disapproval or sympathy  (a disapproving cluck) 3 especially AmE a stupid person  (You dumb cluck, why'd you tell him?)