| DEF | Daily Electronic Feed 
| Others |
| DEF | Data Element Framework
| Others |
| DEF | Data Exchange Format
| Others |
| DEF | Data Exchange Framework
| Others |
| DEF | Days End Farm
| Others |
| DEF | Deaf
| Others |
| DEF | DEFault
| Others |
| DEF | Defaults - definitions
| Others |
| DEF | Defeated Example For
| Others |
| DEF | Defecation
| Others |
| DEF | Defend
| Others |
| DEF | Defender
| Others |
| DEF | Defense Entrepreneurs Forum
| Others |
| DEF | Deferred
| Others |
| DEF | Deficient
| Others |
| DEF | Defile
| Others |
| DEF | Definite
| Others |
| DEF | Definitely
| Others |
| DEF | Defroster
| Others |
| DEF | Delta Echo Force
| Others |
| DEF | Design Exchange Format
| Others |
| DEF | Deutsch Englische Freundschaft
| Others |
| DEF | Development and Evaluation Facility
| Others |
| DEF | Diamond Empowerment Fund
| Others |
| DEF | Diesel Emissions Fluid
| Others |
| DEF | Diesel Exhaust Filter
| Others |
| DEF | Diesel Exhaust Fluid
| Others |
| DEF | Digital Empowerment Foundation
| Others |
| DEF | Direct Equipment Failure
| Others |
| DEF | Dog Egg Federation
| Others |
| DEF | Door Edge Film
| Others |
| DEF | Double Exhaust Filter
| Others |
| DEF | Drengin Elite Fleet
| Others |
| DEF | Driver Education Foundation
| Others |
| DEF | Dungeon Enemies and Fate
| Others |
| DEF | Dutch Elite Force
| Others |
| DEF | Dynamic Efficiency And Fidelity
| Others |
| DEF | Geoworks Esp Assembly header file
| Others |
| DEF | SmartWare II Data definition
| Others |
| DEF | TLink - WLink Linker definition file
| Others |