| Abbreviation | Definition |
|---|---|
| RDE | Rotating Disk Electrode |
| RDL | Radio Design Laboratory |
| RDL | Reliable Detection Limit |
| RDR | Rotating Disk Reactor |
| RDRAM | RAMBUS Dynamic Random Access Memory |
| RDS | Radar Detection System |
| RDTR | Radiator |
| RE | Renewable Energy |
| REA | Runestone Electric Association |
| REA | rural electric administration |
| REACH | Radio Electronics And Computer Hobbyists |
| REC | A Random Electronic Communication |
| REC | Random Environment Contest |
| REC | Rappahannock Electric Cooperative |
| REC | RECeive |
| RECC | Reva Electric Car Company |
| RECC | Rural Electric Convenience Cooperative |
| REDA | Russian Electrical Dynamo of Arutunoff |
| REDM | Reflectorless Electronic Distance Measurement |
| REEV | Range Extended Electric Vehicle |