A boomerang is a tool, typically constructed as a flat airfoil that, when thrown, is designed to spin about an axis perpendicular to the direction of its flight. A returning boomerang is designed to return to the thrower. It is well known as a weapon used by Indigenous Australians for hunting.

Boomerangs have been historically used for hunting, as well as a sport, and entertainment. They are commonly thought of as an Australian icon, and come in various shapes and sizes.

A boomerang is traditionally a long wooden device, although historically boomerang-like devices have also been made from bones. Modern boomerangs used for sport are often made from thin aircraft plywood, plastics such as ABS, polypropylene, phenolic paper, or even high-tech materials such as carbon fibre-reinforced plastics.

Boomerangs come in many shapes and sizes depending on their geographic or tribal origins and intended function. Many people think of a boomerang as the Australian type, although today there are many types of more easily usable boomerangs, such as the cross-stick, the pinwheel, the tumblestick, the boomabird and many other less common types.

According to wikipedia