| HYDRA | Hierarchical Yet Dynamically Reprogrammable Architecture (communications system; US Navy) | 分层但动态可编程架构（通信系统；美国海军） |
| HYDRA | Hierarchical Yet Dynamic Reprogrammable Architecture | 分层但动态可编程体系结构 |
| HYDRA | Hierarchical Yet Dynamic Radio Architecture | 分层但动态的无线电体系结构 |
| HYDRA | Helping You Downtown Roam Around | 帮助您在市区漫游 |