Sig code: route
OS medical abbreviation
OS means "left eye", from the Latin "oculus sinister".
On the ISMP List of Error-Prone Abbreviations. ISMP suggests: Write "left eye".
Each meaning matched at least two public references (4 in all for OS), checked October 23, 2026. The table lists them.
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What OS means
| Meaning | Latin origin | Where used | Checked against |
|---|---|---|---|
| left eye | oculus sinister | Prescriptions, Medication labels |
Example
Training example of an error-prone entry: "OS" on an eye-drop label.
A made-up line that shows the abbreviation in place. It is not about any patient and is not an instruction.
Related abbreviations
Elsewhere on Rivvi
Questions
What does OS mean in medical terms?
OS means "left eye", from the Latin "oculus sinister".
What does OS stand for in Latin?
OS comes from "oculus sinister", meaning "left eye".
Where is OS used?
OS shows up in prescriptions and medication labels. Its category here is sig code: route.
Is OS on the Joint Commission Do Not Use list?
No, but ISMP lists OS as an error-prone abbreviation. ISMP's suggested practice: Write "left eye".