| Abbreviation | Definition |
|---|---|
| ACS | Alternative Current Switch |
| ACSR | Aluminium Conductor Steel Reinforced |
| ACT | Actual Cycle Time |
| ACT | Air Cooled Triode |
| ACT | Akebono Ceramic Technology |
| ACT | Alternative Control Technique |
| ACTM | Accelerated Corrosion Testing Method |
| ACUM | Air Cooled Condensing Unit |
| ADAC | Advanced Digital Acoustic Coding |
| ADACS | Advanced Digital and Analog Collection System |
| ADAM | Active Design and Analysis Modeling |
| ADAM | Advanced Digital Audio Matrix |
| ADB | Advanced Digital Bridge |
| ADC | Advanced Data Converter |
| ADC | Analog Digital Converter |
| ADC | Analog to Digital Converter |
| ADD | Accumulated Degree Days |
| ADD | Android Developer Day |
| ADD | Architectural Design Document |
| ADE | Advanced Development Environment |