The primary line(s) that connects the slower, shorter cable portions of a communications network together. (Seelast mile.) In larger networks, such as the Internet, a backbone consists of high-capacity, high-speed lines that can extend over great distances.
Slang definitions & phrases for backbone
backbone
noun
Integrity and courage; fortitude: If you had any backbone, you would deal with him
backbone in Technology
networking The top level in a hierarchical network. Stub networks and transit networks which connect to the same backbone are guaranteed to be interconnected. See also: Internet backbone. (1998-07-02)