| Acronym | Meaning |
| CB1 | Corrected First Born (perturbation Theory In Atom-ion Collisions) |
| CB2 | Second-order Coulomb Born |
| CBA | Cost-Benefit Analysis |
| CBA | Chemical Blowing Agent |
| CBC | Circulating Bed Combustor (or Incinerator) |
| CBC | Complete Blood Count |
| CBD | Cellulose-binding Domain |
| CBD | Chemical Bath Deposition |
| CBD | Chronic Beryllium Disease |
| CBD | Citrate-bicarbonate-dithionite (sample Treatment In Soil Analysis) |
| CBDE | Chemical And Biological Defence Establishment |
| CBDS | Carcinogenesis Bioassay Data System |
| CBE | Coulomb-Bethe (for Electron-ion Scattering) |
| CBE | Chemical Beam Epitaxy |
| CBEA | Constrained Binary Encounter Approximation |
| CBEC | Concentration-based Exemption Criteria |
| CBED | Convergent-beam Electron Diffraction |
| CBEDP | Convergent-beam Electron-diffraction Pattern |
| CBEN | Center For Biological And Environmental Nan |
| CBER | Center For Biologics Evaluation And Research |
| CBF | Cerebral Blood Flow |
| CBF | Core-binding Factor |
| CBF | Correlated Basis Function |
| CBG | Corticosteroid Binding Globulin |
| CBI | Confidential Business Information |
| CBI | Compliance Biomonitoring Inspection |
| CBIRF | US Marine Corps' Chem/Bio Incident Response Force |
| CBLM | Cluster-bethe-lattice Method (for Electronic-structure Calcns. On Crystals) |
| CBM | Carbon Bond Mechanism (air Pollution Modeling) |
| CBM | Conduction Band Minimum |
| CBM | Constant Boiling Mixture |
| CBMAPDT | Committee On Biologic Markers Of Air-Pollution Damage In Trees |
| CBN | Cubic Boron Nitride |
| CBNM | Central Bureau For Nuclear Measurements |
| CBO | Coulomb Born Oppenheimer |
| CBO | Corrected Born-Oppenheimer (in Calcns. For Mol. Complexes) |
| CBO | Crude Born-Oppenheimer (wave Functions) |
| CBOA | Crude Born-Oppenheimer Approximation |
| CBOD | Carbonaceous Biochemical Oxygen Demand |
| CBOX | Coulomb-Born With No Exchange |
| CBP | Combustion By-Product (from Incineration) |
| CBR | Cosmic Background Radiation |
| CBRA | Coastal Barriers Resource Act |
| CBRNE | Chemical, Biological, Radiological, Nuclear, Explosive |
| CBS | Complete Basis Set |
| CBS | Cystathionine Beta-synthase |
| CBS-FCI | Complete Basis Set-full Configuration Interaction |
| CBS-QCI | Complete Basis Set-quadratic Configuration Interaction |
| CBSA | Chlorobenzenesulfonic Acid |
| CBX | Coulomb-Born Approxn. With Exchange |