| Abbreviation | Definition |
|---|---|
| RASCAL | Rotorcraft Aircrew Systems Concept Airborne Laboratory |
| RASL | Robotics and Autonomous Systems Laboratory |
| RASS | Renin-angiotensin-aldosterone system |
| RAT | Rapid Antigen Test |
| RATL | Ramaiah Advanced Testing Laboratory |
| RATL | Raytheon Analysis Test Laboratory |
| RATS | Rapid Antigen Tests |
| RBC | Red Blood Cell |
| RBCC | red blood cell count |
| RBCU | Red Blood Cell Unit |
| RBG | Random Blood Glucose |
| RBL | Regional Biocontainment Laboratory |
| RBL | Regional Biosafety Laboratory |
| RBN | Research Blending Number |
| RBS | Random Blood Sugar |
| RBW | Red Blood cell Width |
| RCA | Ricinus Communis Agglutinin |
| RCC | Red Cell Concentrate |
| RCCO | Research Conduct and Compliance Office |
| RCFL | Regional Computer Forensics Laboratory |