ETYM Latin.
1. A flask that has two handles; used by Romans for wines or oils.
2. The dilated portion of a canal or duct esp. of the semicircular canals of the ear.
Vessel for holy oil or wine for coronations or rituals.
Ancient Roman flask with two handles and globular body; Anatomy, saclike swelling at end of duct.
Small vessel with a round body and narrow neck, used by the ancient Greeks and Romans for holding oil, perfumes, and so on; ampullae are used in the Christian church for holding water and wine at the Eucharist.

In the inner ear, a slight swelling at the end of each semicircular canal, able to sense the motion of the head.
The sense of balance depends largely on sensitive hairs within the ampullae responding to movements of fluid within the canal.