boomerang (bōō´mərăng´), special form of throwing stick, used mainly by the aborigines of Australia. Other forms of throwing sticks were used by the peoples of ancient Egypt, Ethiopia, and India and by the indigenous peoples of the SW United States. The boomerang is sickle-shaped with arms slightly curved in opposite directions as in a propeller. The trajectory of a boomerang is usually an arc, but in some cases it is a full circle. The boomerang of the Australian aborigines (from whom the name is derived) is made in two types. The smaller boomerang, 12 to 30 in. (30 to 75 cm) long, is used only for sport and is thrown so that it returns to the thrower. The larger war boomerang is 24 to 36 in. (60 to 90 cm) long and does not return; it is used for hunting and warfare.