aerospace engineering Reference Libraries
The boomerang is a flying tool, made of wood or carbon fiber-reinforced plastic, with a curved shape that is often used as a weapon or for sport. They have also been made of bones and come in many different shapes and sizes depending on their geographic or tribal origins and their intended function. The most commonly recognizable type is the returning boomerang which travels in an elliptical...
- The navel or umbilicus.
- In Greek archaeology: A central boss, as on a shield, a bowl, etc.
- A sacred stone in the temple of Apollo at Delphi, believed by the Greeks to mark the 'navel' or exact center-point of the earth.