os in English

os

⇄

os (1), noun, pl.ossa.
(Latin.) a bone.

os

⇄

os (2), noun, pl.ora.
(Latin.) a mouth; opening.

os

⇄

os (3), noun, pl.osar.
(Geology.) an esker.

Os

⇄

Os(no periods),
osmium (chemical element).

OS

⇄

OS(no periods)orO.S.
Old Saxon.