backbone

noun

1. Anatomy. the spinal column; spine.
2. strength of character; resolution.
3. something resembling a backbone in appearance, position, or function.
4. Bookbinding. a back or bound edge of a book; spine.
5. Nautical. a rope running along the middle of an awning, as a reinforcement and as an object to which a supporting bridle or crowfoot may be attached.
6. Naval Architecture. the central fore-and-aft assembly of the keel and keelson, giving longitudinal strength to the bottom of a vessel.

noun

1. a nontechnical name for spinal column
2. something that resembles the spinal column in function, position, or appearance
3. strength of character; courage
4. the main or central mountain range of a country or region
5. nautical the main longitudinal members of a vessel, giving structural strength
6. computing (in computer networks) a large-capacity, high-speed central section by which other network segments are connected

n.

“spine,” early 14c., from back (n.) + bone (n.). Figurative sense of “strength of character” is attested from 1843.

n.

1. spinal column

1. See vertebral column.

The primary line(s) that connects the slower, shorter cable portions of a communications network together. (See last mile.) In larger networks, such as the Internet, a backbone consists of high-capacity, high-speed lines that can extend over great distances.