1.(slang)An Emu. A large flightless bird, native to Australia. Often hunted and used by Australian Aboriginals as a source of food, like a chicken.
2.(slang)A stupid person, so called after the emu which is a very stupid animal.
1. Truck driver: "Shit! I just ran over a bloody boongchook"
2. "Your as dopey as a boongchook"