| Abbreviation | Definition |
|---|---|
| ADSI | American Defense Systems, Inc. |
| ADSI | American Delivery Service, Inc. |
| ADSI | Application Data Systems Inc |
| ADSI | Applied Data Systems Inc |
| ADSI | Applied Data Systems, Inc. |
| ADSM | Advanced Demand Side Management, PLC. |
| ADT | Airtel Digital Television |
| ADT | American District Telegraph |
| ADT | American District Telegraph Company |
| ADTA | Abu Dhabi Tourism Authority |
| ADTI | American Data Technology Inc |
| ADTI | American Data Technology, Inc. |
| ADTL | Advanced Data Technology Laboratory |
| ADTL | Advanced Development Technologies Ltd |
| ADTL | Advanced Development Technologies, Limited |
| ADTL | Aerobel Defense Technology, LTD. |
| ADTS | Advanced Digital Technologies & Solutions |
| ADTS | Advanced Driver Training Services |
| ADTS | Alcohol & Drug Testing Services, L. L. C. |
| ADU | Appliance Distributors Unlimited, Inc. |