| Electrical Resistivity Test | Academic & Science |
| Electronic Reporting Tool | Academic & Science |
| Electrical Resistance Tomography | Academic & Science |
| Electronic Registration and Titling | Academic & Science |
| Electronic Receiver Transmitter | Academic & Science |
| Electronic Registration and Title | Academic & Science |
| Erdenet | Airport Code |
| Exhibits Round Table | Business |
| Elliniki Radiophonia Tikleorassi ( Greek Broadcasting Organization) | Community |
| ESPN Regional Television | Community |
| Everyone Read To .... | Community |
| Early Transmit | Computing |
| Emergency Response Team | Computing |
| Extended Real Time | Computing |
| Edge Roller Technology | Computing |
| Encoder Receiver Transmitter | Electronics |
| Emergency Response Time | Electronics |
| Entirely Retiscent Torpor | General |
| Emergency Remote Teaching | General |
| Emergency Rescue Team | General |
| Encoder Receiver Transmitters | General |
| Evil Red Text | General |
| Early Response Team | General |
| Estimated Runtime The | General |
| Early Ride Time | General |
| Emission Reduction Target | General |
| Elizabeth River Tunnels | General |
| European Rally Trophy | General |
| Evaluation and Repair Tools | General |
| Emergency Roadside Telephone | General |
| Encoder Receiver and Transmitter | General |
| Emergency Response Technician | General |
| Episodes of Regime Transformation | General |
| Early Release Time | General |
| Eugene R Thomas | General |
| Eugene R Thompson | General |
| Exclusive Ride Time | General |
| Earliest Realization Time | General |
| Emotional Repolarization Technique | General |
| Early Ray Termination | General |
| Exclusive Raccoon Time | General |
| Endurance Run Test | General |
| Elite Ramming Team | General |
| eSports Rewards Token | General |
| ESports Reward Token | General |
| Estimated Repair Time | General |
| Empirical Roofline Tool | General |
| Energy Reduction Technique | Governmental |
| Evidence Response Team | Governmental |
| Extra Ride Time | Governmental |
| Environmental Review Tribunal | Governmental |
| Environmental Response Team | Governmental |
| Electronic Recycling Trading | Governmental |
| Environmental Remediation Technologies | Governmental |
| Electronic Recycling and Trading | Governmental |
| Energy Resources and Technologies | Governmental |
| Energy Research Triangle | Governmental |
| Environmental Research Tool | Governmental |
| Excess Retention Tax | Governmental |
| Unión Explosivos Río Tinto, S. A. Ertzaintza | International |
| Estrogen Replacement Therapy | Medical |
| Emergency Room Thoracotomy | Medical |
| Endogenous Reverse Transcription | Medical |
| Enzyme Replacement Therapy | Medical |
| Esophageal Radionuclide Transit | Medical |
| Estrogen Replacement Treatment | Medical |
| external (beam) radiotherapy | Medical |
| Emotion Reintegration Therapy | Medical |
| Execution Reference Time | Military and Defence |
| Emergency Response Team (fema) | Military and Defence |
| Engineer Reconnaissance Team | Military and Defence |
| European Round Table | Regional |
| European Register of Toxicologists | Regional |
| European Registered Toxicologist | Regional |
| Earth Received Time | Space Science |
| Eastern Region Tennis | Sports |
| East Riding Theatre | Sports |
| Enhanced Routing Technology | Technology |
