| Acronym | Meaning |
| CWA | Clean Water Act |
| CWA | Chemical Warfare Agent |
| CWBA | Coulomb-wave Born Approximation |
| CWC | United Nations Chemical Weapons Convention |
| CWD | Chronic Wasting Disease |
| CWF | Coal-water Fuel |
| CWFMS | Combined Wavelength And Frequency Modulation Spectroscopy |
| CWISE | Coated-wire Ion-selective Electrode |
| CWLM | Continuous Working Level Monitor |
| CWM | Center For Waste Management |
| CWM | Chemical Waste Management |
| CWM | Chem. Warfare Materials |
| CWM | Coal Water Mixture |
| CWP | Coal Workers' Pneumoconiosis |
| CWRT | Center For Waste Reduction Technologies |
| CWS | Coal Water Slurry |
| CWS | Community Water System |
| CWT | Centralized Waste Treatment |
| CWTC | Chemical Waste Transportation Council |
| CWTI | Chemical Waste Transportation Institute |
| CWTM | Compound Weaire-Thorpe Model (in Electronic-structure Calcns.) |
| CXAES | Continuous X-ray-induced Auger Electron Spectroscopy |
| CXC | Chandra X-ray Center |
| CXMS | Conversion X-ray Mossbauer Spectroscopy |
| CYCLOPS | Cyclically Ordered Phase Sequence |
| CYP | Cytochrome P450 |
| CZCS | Coastal Zone Color Scanner |
| CZE | Capillary Zone Electrophoresis |
| CZMA | Coastal Zone Management Act |
| CZT | Cadmium Zinc Telluride |
| D-CI | Double Excitations In Configuration Interaction |
| D-SIC | Degeneracy-dependent Self-interaction Correction |
| D.I. | Direct Injection [of Diesel Engines] |
| D/DBP | Disinfection And Disinfection Byproducts |
| D5W | Dextrose 5% In Water |
| DAA | Days After Anthesispar |
| DAA | Diacetone Alcoholpar |
| DAB | Diaminobenzidine (usually 3,3') |
| DAB | Dipole Adapted Basis (wave Function) |
| DAC | Derived Air Concentration |
| DAC | Diamond Anvil Cell |
| DAD | Diode Array Detector |
| DADI | Direct Analysis Of Daughter Ions |
| DADMAC | Diallyldimethylammonium Chloride |
| DAEM | Distributed Activation Energy Model |
| DAF | Decay-accelerating Factor |
| DAF | Diallyl Fumarate |
| DAF | Dissolved Air Flotation |
| DAF | Distributed Approximating Functional (in Study Of Quantal Wave-packet Propagation) |
| DAFLOW | Diffusion Analogy Flow [model] |