\ ˈäs How to pronounce os (audio) \
plural ossa\ ˈä-​sə How to pronounce ossa (audio) \

Definition of os

 (Entry 1 of 4)

\ ˈōs How to pronounce os (audio) \
plural ora\ ˈȯr-​ə How to pronounce ora (audio) \

Definition of os (Entry 2 of 4)

Definition of Os (Entry 3 of 4)

osmium

Definition of OS (Entry 4 of 4)

1 [Latin oculus sinister] left eye
2 Old Style
3 operating system
4 out of stock

First Known Use of os

Noun (1)

15th century, in the meaning defined above

Noun (2)

1737, in the meaning defined above

History and Etymology for os

Noun (1)

Latin oss-, os — more at osseous

Noun (2)

Latin or-, os — more at oral

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Time Traveler for os

Time Traveler

The first known use of os was in the 15th century

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Cite this Entry

“Os.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/os. Accessed 5 Jul. 2020.

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More Definitions for os

os

noun
\ ˈäs How to pronounce os (audio) \
plural ossa\ ˈäs-​ə How to pronounce ossa (audio) \

Medical Definition of os

 (Entry 1 of 4)

os

noun
\ ˈōs How to pronounce os (audio) \
plural ora\ ˈōr-​ə, ˈȯr-​ə How to pronounce ora (audio) \

Medical Definition of os (Entry 2 of 4)

Medical Definition of Os (Entry 3 of 4)

osmium

Medical Definition of OS (Entry 4 of 4)

left eye used in writing prescriptions

History and Etymology for os

Abbreviation

Latin oculus sinister

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More from Merriam-Webster on os

Rhyming Dictionary: Words that rhyme with os

Spanish Central: Translation of os

Nglish: Translation of os for Spanish Speakers

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