| Abbreviation | Definition |
|---|---|
| BU | BackUp |
| BU | Broken Up |
| BUC | Back-Up Computer |
| BUC | BUCkhorn, California (Ground Satellite Tracking Data Network station) |
| BUDS | Back-Up Digital System |
| BUFF | BUFfer |
| BUOU | Back-Up Optical Unit |
| BUR | Back-Up Rate |
| BUV | Backscatter Ultra- Violet |
| BW | BandWidth |
| BW | BridgeWire |
| BX | Box |
| BYP | BYPass |
| C | Candle |
| C | Capacitance |
| C | Celsius |
| C | Centigrade |
| C | Coefficient |
| C | Complete |
| C | Constant |