1. To make non-functional or greatly degraded in performance. "That big ray-tracing program really hoses the system." See hosed.
2. A narrow channel through which data flows under pressure. Generally denotes data paths that represent performance bottlenecks.
3. Cabling, especially thick Ethernet cable. This is sometimes called "bit hose" or "hosery" (a play on "hosiery") or "etherhose". See also washing machine.