| Acronym | Meaning |
| DCQAP | Data Collection Quality Assurance Plan |
| DCRF | Die Casting Research Foundation |
| DCS | Distributed Control System |
| DCTL | Direct Coupled Transistor Logic |
| DCTP | Direct-current Tast Polarography |
| DCTS | Discharging Current Transient Spectroscopy |
| DCXD | Double Crystal X-ray Diffraction |
| DCXRD | Double Crystal X-ray Diffraction |
| DDAB | Didodecyldimethylammonium Bromide |
| DDAF | Dicretized Distributes Approximating Function (propagator |
| DDBJ | DNA Data Bank Of Japan |
| DDE | Dichlorodiphenyldichloroethylene |
| DDF | Depth Distribution Function |
| DDIM | Dry Deposition Inferential Monitoring |
| DDLS | Depolarized Dynamic Light Scattering |
| DDM | Decoupled Direct Method |
| DDM | 4,4'-diaminodiphenyl Methane |
| DDM | Denuder Difference Method |
| DDMO | Differential Density Matrix Overlap (index |
| DDP | Didecyl Phthalate |
| DDQRPA | Double Direct Quadratic Random Phase Approximation |
| DDRP | Direct Delayed Response Program (for Long Term Effects Of Acid Rain) |
| DDRPA | Double Direct Random Phase Approximation |
| DDSC | Dynamic Differential Scanning Calorimetry |
| DDT | Dichlorodiphenyltrichloroethane |
| DDTA | Derivative Differential Thermal Analysis |
| DDVP | Dimethyl Dichlorovinyl Phosphate (dichlorovos REG: 62737) |
| DDX | Isomers And Metabolites Of DDT |
| DE | Dynamics Explorer (spacecraft) |
| DE | Destruction Efficiency |
| DEA | Dissociative Electron Attachment |
| DEA | Drug Enforcement Administration |
| DEBITS | Deposition Of Biogeochemically Important Trace Species |
| DEC | Department Of Environmental Conservation |
| DECC | Diethylcarbamyl Chloride |
| DECENT | Distribution Of Exact Classical Energy Transfer Approximation |
| DECODE | Dipolar Echo Decay |
| DECSY | Double-quantum Coherence Echo Correlated Spectroscopy |
| DED | Death Effector Domain |
| DEF | Dose Effect Factor |
| DEFT | Driven Equilibrium Fourier Transform |
| DEG | Diethylene Glycol |
| DEGBAC | Diethylene Glycol-bis(allyl Carbonate) |
| DEGM | Degenerate Electron Gas Model |
| DEGMBE | Diethylene Glycol Mono-n-Bu Ether |
| DEHP | Bis(2-ethylhexyl) Phthalate |
| DEIA | DNA Enzyme Immunoassay |
| DEIS | Draft Environmental Impact Statement |
| DELCD | Dry Electrolytic Conductivty Detector |
| DELFIA | Dissociation-enhanced Lanthanide Fluoroimmunoassay |