- plural of os1.
- a mountain in E Greece, in Thessaly. 6,490 feet (1,978 meters).
- the plural of os 2
- a mountain in NE Greece, in E Thessaly: famous in mythology for the attempt of the twin giants, Otus and Ephialtes, to reach heaven by piling Ossa on Olympus and Pelion on Ossa. Height: 1978 m (6489 ft)
