Pronunciation: (hed'gēr"),[key] —n. 1. any covering for the head, esp. a hat, cap, bonnet, etc.
2. a protective covering for the head, as a steel helmet or football helmet.
3. the parts of a harness about the animal's head.
4. Orthodontics Informal.a device worn on the head and attached by wires and elastic bands to braces in the mouth, used to create backward tension in the process of repositioning protruding teeth.
5. Mining.a headframe and its machinery.