| orch | orchitis |
|---|---|
| ORD | optical rotatory dispersion; oral radiation death |
| ORDS | Office of Research, Demonstration, and Statistics |
| ORE | oil retention enema |
| OREF | Orthopedic Research and Education Foundation |
| ORF | open reading frame |
| orf | open reading frame |
| Org, org | organic |
| ORIF | open reduction with internal fixation |
| OrJ | orange juice |