| Abbreviation | Definition |
|---|---|
| At | Astatine |
| AT% | Atomic Percent |
| ATase | Amidophosphoribosyltransferase |
| ATC | Active Thermal Convection |
| ATC | Alcohol Type Concentrate |
| ATC | Automatic Temperature Compensation |
| ATCS | Active Thermal Convection System |
| ATcT | Active Thermochemical Tables |
| ATGAS | Automated Tracer Gas Analysis System |
| ATMP | Amino Trimethylene Phosphonic Acid |
| ATOM | Ancient Teachings Of The Masters |
| ATP | Adenosine Tri-Phosphate |
| ATP | All Trace Particles |
| ATP | Ambient Temperature and Pressure |
| ATP | Ambient Temperature Pressure |
| ATPS | Atmospheric, Temperature, Pressure, Saturated |
| ATRA | All Trans Retinoic Acid |
| AtZn-MP | Arabidopsis thaliana Zinc-MetalloProtease |
| Au | Gold |
| AVID | Advanced Vaporless IPA (IsoPropyl Alcohol) Dryer |