Cooney means something bad/ugly/stupid/crazy- a general 'mean' word. Another way of describing it is that it is 'butterz to da max' lol.
"Ya' little cooney bitch!"
"She's cooney in da brain!"
"That dress she was wearing was bare cooney!"
"This is not good! This is like, COONEY!"
"Shut your little cooney mouth, ya cooney bastard!"