| RN | radionuclide; red nucleus; Registered Nurse; registry number; residual nitrogen; reticular nucleus |
|---|---|
| RNA | radionuclide angiography; Registered Nurse Anesthetist; ribonucleic acid; rough, noncapsulated, avir... |
| RN-C | registered nurse-certification |
| RNFP | Registered Nurse Fellowship Program |
| RRN | returning [for advanced studies] registered nurse |