| Acronym | Meaning |
| BWCC | Brillouin-Wigner Coupled-cluster (theory) |
| BWCCD | Brillouin-Wigner Coupled-cluster (with) Double (excitation) |
| BWCCSD | Brillouin-Wigner Coupled-cluster (with) Single (and) Double (excitations) |
| BWEN | Brillouin-Wigner (second-order Perturbation Theory With) Epstein-Nesbet (energy Denominators) |
| BWIP | Basalt Waste Isolation Project |
| BWO | Backward Wave Oscillator |
| BWPT | Brillouin-Wigner Perturbation Theory |
| BWR | Boiling Water Reactor |
| BXE | Bombardment-induced X-ray Emission |
| BZ | 3-quinuclidinyl Benzilate (chemical Warfare Agent) |
| BZR | Benzodiazepine Receptor |
| C.I. | Color Index |
| C4 | Controlled Collapse Chip Connection |
| C4S | Chemical Shift-specific Slice Section |
| CA | Chromosomal Abberation |
| CA | Cellulose Acetate |
| CA | Collision Activation |
| CA | Corrective Action |
| CAA | Clean Air Act Of 1970 |
| CAA | Computer Aided Analysis |
| CAA | Contaminant Analysis Automation |
| CAAA | Clean Air Act Amendments (of 1990) |
| CAALS | Consortium On Automated Analytical Laboratory Systems |
| CAAMP | Canadian Acid Aerosol Measurement Program |
| CAASE | Computer Assisted Area Source Emissions |
| CAAT | Johns Hopkins Center For Alternatives To Animal Testing |
| CAB | Cellulose Acetate Butyrate |
| CAB | Combination Of Atomic Boxes (mo Method) |
| CAB | Continental Arc Basalt |
| CAB | Core And Bond (molecular Partitioning Method) |
| CABG | Coronary Artery Bypass Graft |
| CAC | Critical Aggregation Concentration |
| CAC | Carbon Arc Cutting |
| CAC | Continuous Annular Chromatograph |
| CACGP | Committee On Atmospheric Chemistry And Global Pollution |
| CAD | Computer-Aided Design |
| CAD | Collisionally Activated Dissociation |
| CAD | Coronary Artery Disease |
| CADASIL | Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts And Leukoencephalopathy |
| CADAT | Computer Aided Design And Testing |
| CADD | Computer Aided Drafting And Design |
| CADD | Computer Aided Drug Design |
| CADE | Computer Aided Deposit Evaluation |
| CADRE | Computer Aided Data And Retrieval And Evaluation Software |
| CADW | Converged-adiabatic Distorted-wave (quantum Calcn. Method) |
| CAE | Capillary Affinity Electrophoresis |
| CAE | Capillary Array Electrophoresis |
| CAE | Cis-acting Element |
| CAE | Computer-aided Engineering |
| CAE | Constant Analyzer Energy |