| OB-US | obstetrical ultrasound [examination of the fetus] |
|---|---|
| O&E | observation and examination |
| OSCE | objective structured clinical examination |
| OX | optic chiasma; oxacillin; oxalate; oxide; orthopedic examination; oxytocin |
| PAME | preanesthesia medical examination; primary amebic meningoencephalitis |