| OS | left eye [Lat. oculus sinister]; occipitosacral; occupational safety; office surgery; Omenn syndrome... |
|---|---|
| OSF | organ system failure; osteoclast-stimulating factor; outer spiral fiber; overgrowth stimulating fact... |
| OTD | oculotrichodysplasia; oral temperature device; organ tolerance dose |
| SCO | sclerocystic ovary; somatic crossing-over; subcommissural organ |
| SOSF | single organ system failure |