| Abbreviation | Definition |
|---|---|
| R&D | Research & Development |
| R&M | routine and manual |
| R&S | recruitment and selection |
| RA | radial |
| RA | radial artery |
| RA | radioactive |
| RA | radioactivity |
| RA | radioassay |
| RA | radiographic absorptiometry |
| RA | radionuclide angiography |
| RA | ragweed antigen |
| RA | receptor antagonist |
| RA | rectus abdominis |
| RA | refractory anaemia |
| RA | refractory ascites |
| RA | regional anaesthesia |
| RA | regression analysis |
| RA | renal agenesis |
| RA | renal artery |
| RA | research associate |