| Acronym | Definition |
|---|
| DEC | Digital Equipment Corporation |
| DEC | December |
| DEC | Decimal |
| DEC | Decision |
| DEC | Department of Environmental Conservation |
| DEC | Department of Environment and Conservation (NSW, Australia) |
| DEC | Decade |
| DEC | Declared |
| DEC | Decorated |
| DEC | Decode |
| DEC | Decrease |
| DEC | Declaration |
| DEC | Decorative |
| DEC | Deceased |
| DEC | Division for Early Childhood (Council for Exceptional Children) |
| DEC | Drug Endangered Children (program) |
| DEC | Display Energy Certificate (UK energy certificate for commercial buildings) |
| DEC | Declination |
| DEC | Decrement |
| DEC | Disasters Emergency Committee (UK) |
| DEC | Departamento de Engenharia Civil (Portugese) |
| DEC | Diplôme d'Expertise Comptable (French: Diploma of Chartered Accounting) |
| DEC | Democratic Executive Committee (politics; various locations) |
| DEC | Division of Environmental Chemistry (various locations) |
| DEC | Division des Examens et Concours (French: Division of Examinations and Competitions) |
| DEC | Devon Energy Corporation (various locations) |
| DEC | Diplôme d'Etudes Collégiales (French: College Diploma; Canada) |
| DEC | Drug Enforcement Commission (Zambia) |
| DEC | Development Education Centre |
| DEC | Digital Electronic Control |
| DEC | Data Entry Clerk |
| DEC | Dietary Energy Consumption (food security) |
| DEC | Dépannage Entretien Chauffage (French: Heating Maintenance Troubleshooting) |
| DEC | Department Executive Committee (various organizations) |
| DEC | Diethylcarbamazine |
| DEC | District Export Council |
| DEC | Département d'Etudes Cognitives (French: Department of Cognitive Studies) |
| DEC | Disability Empowerment Center (various locations) |
| DEC | Developpement Economique Canada (French: Canada Economic Development) |
| DEC | Disaster Emergency Communications |
| DEC | Durban Exhibition Centre (South Africa) |
| DEC | Digital Entertainment Center (various companies) |
| DEC | Digital Electronic Computer |
| DEC | Directory Experts Conference |
| DEC | Double Error Correction |
| DEC | Decoding Circuit |
| DEC | Decryption |
| DEC | Data Exchange Center |
| DEC | Digital Ethernet Personal Computer |
| DEC | Digital Entertainment Center |
| DEC | Decompressor |
| DEC | Diethyl Carbonate |
| DEC | Decrescendo |
| DEC | Declarations Page (insurance) |
| DEC | Diagnostic Expertise Conseil (French: Diagnostic Expertise Consulting) |
| DEC | Diversified Energy Corporation |
| DEC | Diplôme d'Etudes Chorégraphiques (French: Diploma of Choreography Studies) |
| DEC | Delaware Electric Cooperative |
| DEC | Digital Engine Control |
| DEC | Device Clear |
| DEC | District Environmental Commission (Vermont) |
| DEC | Distance Education Center |
| DEC | Direct Energy Conversion |
| DEC | Diabetes Education Center |
| DEC | Decatur, GA, USA (airport code) |
| DEC | Dépôts Électrolytiques et Chimiques (French metal processing company) |
| DEC | Department of Environmental Control |
| DEC | Development Experience Clearinghouse (USAID) |
| DEC | Drug Evaluation Committee |
| DEC | Dévéloppement Économique Canada pour les Régions du Québec (French) |
| DEC | Direccion de Estadistica y Censo (Spanish) |
| DEC | Doctor of Economics |
| DEC | Daily Effective Circulation (advertising) |
| DEC | Deratting Exemption Certificate (shipping) |
| DEC | DEME Environmental Contractors |
| DEC | Distributed Education Center |
| DEC | Developmental Evaluation Clinic |
| DEC | Dictionnaire Explicatif et Combinatoire (French: Explanatory Combinatorial Dictionary) |
| DEC | Department of the Environment and Conservation |
| DEC | Director's Executive Council |
| DEC | Diplôme d'Etudes Complémentaires (French: Complementary Diploma; Belgium) |
| DEC | Decatur, IL, USA - Decatur Municiple Airport (Airport Code) |
| DEC | Digital Effects Control (photography, used in digital cameras color settings) |
| DEC | Data Evolution Corporation (New Orleans, LA and Ontario, Canada) |
| DEC | Development and Education Committee |
| DEC | Design, Engineering and Computing |
| DEC | Douglas Electric Cooperative |
| DEC | Diamond Entertainment Corporation (video company) |
| DEC | Defence Equipment Capability |
| DEC | Drug Education Coordinator |
| DEC | Dream Exotics Cars (French car club) |
| DEC | Deductible Employee Contribution (US IRS) |
| DEC | Drug Evaluation in Children |
| DEC | Disease Endemic Country |
| DEC | Digital Extended Command |
| DEC | Defence Estates Committee |
| DEC | Diamond Edge Communications |
| DEC | Département d'Etudes des Combustibles (French: Department of Fuel Studies; Commissariat à l'Energie Atomique et aux Energies Alternatives) |
| DEC | Department of Environmental Conventions |
| DEC | Dingwall Evangelical Church (UK) |
| DEC | DOE Environmental Checklist |
| DEC | Disposable Enterics Card |
| DEC | Data Equivalence Class |
| DEC | Design Error Check |
| DEC | Delta Executive Controller |
| DEC | Dispersion Equalization Card |
| DEC | Downhill Etc Crew (bike jumping group) |