| Abbreviation | Definition |
|---|---|
| RAK | Right Above Knee amputation |
| RAM | Repetitive Assistance Malfunction |
| RAM | Reticular Action Model |
| RANK | Receptor Activator Of Nf Kappa |
| RANK | receptor activator of nuclear factor kB |
| RAP | Reinforcing AIDS Prevention |
| RAP | Renal Artery Pressure |
| RAP | Retinal Angiomatous Proliferation |
| RAP | Right Atrial Pressure |
| RAPD | Relative Afferent Pupillary Defect |
| RAPID | Ruggedized Advanced Pathogen Identification Device |
| RAQ | Rarely Asked Question |
| RAR | Rapidly Adapting Receptor |
| RAS | Redirecting Antibody Specificity |
| RAS | Reticular Activating System |
| RAS | Reticular Activation System |
| RASA | Rotation Around a Stationary Axis |
| RASF | Rheumatoid Arthritis Synovial Fibroblast |
| RAT | Radical Anxiety Termination |
| RATX | Radiation Therapy |