| DAA | Data Access Arrangement |
| DAB | Designated Audit Body |
| DAC | Digital-to-Analog Converter |
| DAM | Digital Asset Management |
| DAP | Donor Acceptor Pairs (recombination) |
| DARPA | Defense Advanced Research Projects Agency (now ARPA) |
| DART | Dual Asynchronous Receiver Transmitter |
| DAS | Dimer-Adatom Stacking; Direct Absorption Spectroscopy; Digital Audio System |
| DASSL | Differential Algebraic System SoLver |
| DATALEED | LEED w/ extremely fast data acquisition&computer processing |
| DATC | Design Automation Technical Committee (IEEE) |
| DAV | Distributed Authoring and Versioning |
| D/B | Die Bonding |
| dBa | Adjusted decibel |
| DBE | Donor Bound Exciton (process) |
| DBMS | DataBase Management System |
| DBR | Distributed Bragg Reflector |
| DBRT | Double Barrier Resonant Tunneling |
| DBS | Direct Broadcast Satellite |
| DC | Direct Current; Dielectric Constant |
| DCA | Direct Chip Attachment |
| DCAS | Defense Contract Administration Service |
| DCATS | Double-Contained Acid Transfer System |
| DCC | Dynamic Channel Change |
| DCCF | Discounted Cumulative Cash Flow |
| DCD | DC Demagnitization (as opposed to AC) |
| DCE | Distributed Computer Environment |
| DCFL | Direct Coupled FET Logic |
| DCG | Domain Coordination Group |
| DCL | Digital Command Language; Display Communication Log |
| DCMA | Defense Contract Management Agency |
| DCMC | Defense Contract Management command |
| DCMI | Dublin Core Metadata Initiative |
| DCOM | Distributed Component Object Model |
| DCPAT | Dual CEPT Primary Access Transceiver |
| DCS | DiChloroSilane |
| DCX | Zsoft multipage Paintbrush image format |
| DD | Deformation Donor; Double Donor; Dislocation Density; Double Density |
| DDL | Device Description Language |
| DDMS | Defect Data Management System |
| DDR | Double Data Rate |
| DDS | Direct Digital Synthesis |
| deci | 1.00E-1 (1/10; symbolized by the prefix d) |
| DECT | Digital Enhanced Cordless Telephone |
| DEDS | Discrete Event Dynamic Simulation |
| DEG | Dimensional Electron Gas |
| deka | 1.00E+1 (10/1; symbolized by the prefix da) |
| DEMS | Digital Electronic Messaging Service |
| DEMUX | Demultiplexer |
| DES | Data Encryption Standard; Display Equipment Status |
| DESC | Defense Electronics Supply Center |
| DF | DarkField |
| DFB | Distributed FeedBack |
| DFESH | Design For Environment, Safety, and Health |
| DFLP | Design For Low Power |
| DFM | Design For Manufacturability |
| DFR | Design For Reliability |
| Density Functional Theory; Digital Fourier Transform; Design For Testability; Design |
