os
1 of 4noun (1)
ˈäs 
plural ossa ˈä-sə
: bone
os
2 of 4noun (2)
ˈōs
plural ora ˈȯr-ə
: orifice
Os
3 of 4symbol
osmium
OS
4 of 4abbreviation
1
[Latin oculus sinister] left eye
2
Old Style
3
operating system
4
out of stock
Word History
Etymology
Noun (1)
Latin oss-, os — more at osseous
Noun (2)
Latin or-, os — more at oral
First Known Use
Noun (1)
15th century, in the meaning defined above
Noun (2)
1737, in the meaning defined above
Medical Definition
os 1 of 4
noun
ˈäs
plural ossa ˈäs-ə
: bone see os calcis, os coxae
os
2 of 4noun
ˈōs
plural ora ˈōr-ə, ˈȯr-ə
: orifice see external os, internal os, per os
Os
3 of 4symbol
osmium
OS
4 of 4abbreviation
left eye —used in writing prescriptions