| OS | left eye [Lat. oculus sinister]; occipitosacral; occupational safety; office surgery; Omenn syndrome... |
|---|---|
| OSCC | oral squamous cell carcinoma |
| OTD | oculotrichodysplasia; oral temperature device; organ tolerance dose |
| OTF | octamer-binding transcription factor; oral transfer factor |
| OTFC | oral transmucosal fenatyl citrate |