| OC | obstetrical conjugate; occlusocervical; office call; on call; only child; optic chiasma; oral contra... |
|---|---|
| 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 |