A bone (used chiefly in Latin names of individual bones, e.g. os trapezium).→ ossa
- ‘Besides this unambiguous distinguishing character, a second, derived character, exists which is particular to the Carnivora: in the wrist the joint bones, scaphoid, lunate, and os centrale, are fused.’
- ‘In this group, the cortex of the os sacrum was destroyed and had a spongelike rather than compact appearance.’
An opening or entrance to a passage, especially one at either end of the cervix of the uterus.→ ora
- ‘The internal os closes by 3 days, the external os by 3 weeks.’
- ‘The distance between the internal and external os was measured both as a straight line and also as a curved line along the endocervical canal.’
Mid 18th century: from Latin, mouth.
1(in calculating dates) Old Style.
5(in the UK) Ordnance Survey.
6(as a size of clothing) outsize.
7Out of stock.
The chemical element osmium.