A sound made to annoy those around you. A random noise made for no reason; a noise made when someone says something so stupid that it doesn't warrant a real response.
I walk through the living room and see my sister sitting on the couch. I walk past her and say, "Chicka."
Idiot man: Hey baby! You lookin' for a date? Some sex? You must be tired because you were running through my mind all day.