| Abbreviation | Definition |
|---|---|
| ATC | Ancient Traditional Concept |
| ATC | Average Time to Completion |
| ATD | A Terrific Department |
| ATDNSHINC | Any Time Day and Night, Sundays and Holidays INCluded |
| ATF | Activating Transcription Factor |
| ATF | After The Future |
| ATG | Advanced Technology Group |
| ATIMA | As Their Interests May Appear (insurance) |
| ATM | After The Money |
| ATM | Against The Mainstream |
| ATO | Approved Time-Off |
| ATO | Assembled To Order |
| ATP | Across The Pond |
| ATP | Advanced Test Products |
| ATP | Available To Promise |
| ATR | Accuracy Timeliness Responsiveness |
| ATRI | American Transportation Research Institute |
| ATS | Aggravate The Secretaries |
| ATS | Air Tools Store |
| ATS | Angel The Series |