| Acronym | Meaning |
| CDI | Chronic Daily Intakes |
| CDI | Continuous Deionization |
| CDIAC | Carbon Dioxide Information Analysis Center |
| CDIF | Component Development And Integration Facility (MHD Channel Generator Plant |
| CDIR | Carbon Dioxide Information Repository |
| CDK | Cyclin Dependent Kinase |
| CDKI | Cyclin Dependent Kinase Inhibitor |
| CDM | Capacitive Discharge Mode |
| CDM | Clean Development Mechanism |
| CDM | Cold Dark Matter |
| CDMA | Code Division Multiple Access |
| CDMO | Composite Dimensional Manganese Oxide |
| CDMS | Cryogenic Dark Matter Search |
| CDNA | Complementary DNA |
| CDO | Controlled Decomposition/oxidation |
| CDOC | Colored Dissolved Organic Carbon |
| CDOE | Charge-dependent Orbital Exponent Theory |
| CDOM | Chromophoric Dissolved Organic Matter |
| CDOM | Colored Dissolved Organic Matter |
| CDP | Contracted Density Product (in Simplification Of MO Calcns.) |
| CDP | Cytidine 5'-diphosphate |
| CDPF | Catalytic Diesel Particulate Filter |
| CDPT | Constant Denominator Perturbation Theory |
| CDRE | Convolution Difference Resolution Enhancement |
| CDRH | Center For Devices And Radiological Health |
| CDRP | Carbon Dioxide Research Program (of US Department Of Energy) |
| CDS | Compliance Data System (US EPA Air Database) |
| CDS/ISIS | CDS/Integrated Set Of Information System |
| CDSI | Committee On The Dissemination Of Scientific Information |
| CDT | Critical Dissolution Time (synthetic Fiber And Polymer Property) |
| CDV | Capacitor Discharge Vaporization |
| CDW | Circumpolar Deep Water |
| CDW | Coulomb Distorted Wave (for Scattering Calcns.) |
| CDW | Charge-density Wave |
| CDW | Continuum Distorted Wave |
| CDW-EIS | Continuum Distorted Wave-eikonal Initial State (in Collisions) |
| CDW-IA | Continuum Distorted Wave-impulse Approxn. |
| CDWA | Continuum Distorted-wave Approxn. (for Scattering Calcns.) |
| CDWF | Correlated-determinant Wave Function |
| CE | Capillary Electrophoresis |
| CE/ESIMS | Capillary Electrophoresis/electrospray Ionization Mass Spectrometry |
| CEA | Cost-Effectiveness Analysis |
| CEA | Carcinoembryonic Antigen |
| CEACAM1 | Carcinoembryonic Antigen Cell Adhesion Molecule 1 |
| CEAM | Center For Exposure Assessment Modeling |
| CEARC | Canadian Environmental Assessment Research Council |
| CEAREX | Coordinated Eastern Arctic Experiment |
| CEARP | Comprehensive Environmental Assessment And Response Program |
| CEAS | Cavity-enhanced Absorption Spectroscopy |
| CEAS | Coulometric Electrode Array System |