1

os

play
noun \ˈäs\

Definition of os

plural

ossa

play \ˈä-sə\
  1. :  bone

Origin and Etymology of os

Latin oss-, os — more at osseous


First Known Use: 15th century


2

os

play
noun \ˈōs\

Definition of os

plural

ora

play \ˈȯr-ə\
  1. :  orifice

Origin and Etymology of os

Latin or-, os — more at oral


First Known Use: 1737


Os

symbol

Definition of Os

  1. osmium

Other Chemical Engineering Terms


OS

abbreviation

Definition of OS

  1. 1 [Latin oculus sinister] left eye

  2. 2 Old Style

  3. 3 operating system

  4. 4 out of stock


Medical Dictionary

1

os

play
noun \ˈäs\

Medical Definition of os

plural

ossa

\ˈäs-ə\play

2

os

play
noun \ˈōs\

Medical Definition of os

plural

ora

\ˈōr-ə, ˈȯr-ə\play

Os

symbol

Medical Definition of Os

  1. osmium


OS

abbreviation

Medical Definition of OS

  1. left eye—used in writing prescriptions

Origin and Etymology of os

Latin oculus sinister


Learn More about os


Seen and Heard

What made you want to look up os? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

to decrease in size, extent, or degree

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

  • alphabet-magnets
  • Which is the correct spelling?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ