| OO | oophorectomy |
|---|---|
| OOA | outer optic anlage |
| OOB | out of bed |
| OOH | out-of-hospital |
| OOH/CA | out-of-hospital cardiac arrest |
| OOLR | ophthalmology, otology, laryngology, and rhinology |
| OOM, oom | oogonial metaphase |
| OOR | out-of-room |
| OORR | orbicularis oculi reflex response |
| OOW | out of wedlock |