| Abbreviation | Definition |
|---|---|
| AD | All Day |
| AD | Always Demanding |
| AD | Always Dependable |
| AD | Art Director |
| AD | Assistant Deputy |
| AD | Assistant Director |
| ADA | Apprentice Dark Angel |
| ADAF | Associate Director of Administration and Finance |
| ADC | Assistant District Commissioner |
| ADDA | Advanced Data Dictionary Architect |
| ADI | Advanced Driving Instructor |
| ADIA | Approved Driving Instructor - Advanced |
| ADIF | Administrador De Infraestructuras Ferroviarias |
| ADM | Assistant Deputy Minister |
| ADOF | Associate Director of Finance |
| ADPSO | Automatic Data Processing Security Officer |
| ADPSSO | Automatic Data Processing System Security Officer |
| ADRP | Assistant Director for Research and Planning |
| ADS | Associate Development Scheme |
| ADTS | Applicant Document Tracking System |