The central structural beam along the bottom of a ship's hull; by extension, any similar supporting frame in an aircraft or building.

Fossilized bones or teeth of ancient mammals such as elephants and rhinoceroses, used in traditional Chinese medicine for their calming and astringent properties.

The sternum or breastbone of a bird.

The bones of a dragon, appearing in mythology and early historical texts such as the 史记 shǐ​jì