| ORS | olfactory reference syndrome; oral rehydration solution; oral surgery, oral surgeon; Orthopaedic Res... |
|---|---|
| CEI | character education inquiry; converting enzyme inhibitor |
| OCR | oculocardiac reflex; oculocerebrorenal [syndrome]; optical character recognition |
| OCP | octacalcium phosphate; ocular cicatricial pemphigoid; oral case presentation; oral contraceptive pil... |
| OET | oral endotracheal tube; oral esophageal tube |