| Acronym | Meaning |
| DAFNE | Double Annular Factory For Nice Experiments |
| DAFS | Diffraction Anomalous Fine Structure |
| DAHS | Data Acquisition And Handling System |
| DAIM | Deformed Atoms In Molecules |
| DAIP | Diallyl Isophthalate |
| DAIRS | Differential Absorption Infrared Sensor |
| DAL | Defect Action Level |
| DAM | Military Applications Branch (French; Direction Des Applications Militaires) |
| DAM | Diallyl Maleate |
| DANTE | Delays Alternating With Nutations For Tailored Excitation |
| DAP | Diallyl Phthalate |
| DAP | Distributed Array Processor |
| DAPC | Department Of Air Pollution Control |
| DAPK | Death-associated Protein Kinase |
| DAPS | Disappearance Potential Spectroscopy |
| DARA | Disposal Area Remedial Action |
| DARC | Description |
| DARC | Dielectric Antireflection Coating |
| DARMA | Deterministic Autoregressive Moving Average |
| DARPA | Defense Advanced Research Projects Agency (Department Of Defense) |
| DART | Developmental And Reproductive Toxicology Database (NLM) |
| DARTAB | Dose And Risk Assessment Tabulation |
| DAS | Days After Sowing |
| DAS | Dendrite Arm Spacing |
| DAS | Direct Absorption Spectroscopy |
| DAS | Double Antibody Sandwich |
| DAS | Dynamic Angle Spinning |
| DASCO | Discriminant Analysis With Shrunken Covariances |
| DASD | Direct Access Storage Device |
| DASH | Dynamic Allele-specific Hybridization |
| DASHO | Designated Agency Safety And Health Official |
| DASP | Discontinuous Activated Sludge Process |
| DAST | Diethylaminosulfur Trifluoride |
| DATBP | Diallyl Tetrabromophthalate |
| DAU | Drug Abuse Urine |
| DAVES | Desorption And Vapor Extraction System |
| DAVINS | Direct Analysis Of Very Intricate Nmr Spectra |
| DAW | Dry Active Waste |
| DAXRT | Double-axis Reflection X-ray Topography |
| DBD | DNA Binding Domain |
| DBD | Dielectric Barrier Discharge |
| DBDPO | Decabromodiphenyl Oxide |
| DBE | Deep Basin Experiment |
| DBE | Distorted-wave Born Exchange |
| DBEP | Bis(2-butoxyethyl) Phthalate |
| DBF | Dibutyl Fumarate |
| DBI | Diazepam Binding Inhibitor |
| DBL | Diffusive Boundary Layer |
| DBMS | Data Base Management System |
| DBP | Dibutyl Phthalate |