| Abbreviation | Definition |
|---|---|
| DE | Dynamics Explorer |
| DEA | Deployed Electronics Assembly |
| DEACT | DEACTivate |
| DEAPS | Department of Earth Atmosphere and Planetary Science |
| DEC | Declination |
| DECL | Direct Energy Conversion Laboratory |
| DECNET | Digital Equipment Corporation Network |
| DECOM | DECOMmutator |
| DECR | DECRease |
| DECS | Departmenty of Engineering, Civil Engineering Services (Vandenberg Air Force Base) |
| DECU | Data Exchange Control Unit |
| DED | DEDicated |
| DEDA | Data Entry and Display Assembly |
| DEE | Digital Events Evaluator |
| DEF | DEFinition |
| DEFL | DEFLect |
| DEG | DEGree |
| DEI | Design Engineering Identification |
| DEIS | Design Engineering Inspection Simulation |
| DEIS | Design Evaluation Inspection Simulator |