| OG | obstetrics and gynecology; occlusogingival; oligodendrocyte; optic ganglion; orange green; orogastri... |
|---|---|
| ON | occipitonuchal; office nurse; onlay; optic nerve; orthopedic nurse; osteonecrosis; osteonectin; over... |
| ONG | optic nerve glioma |
| OOA | outer optic anlage |
| OR | a logical binary relation that is true if any argument is true, and false otherwise; [o]estrogen rec... |