backbone
noun
[ ˈbakbəʊn ]
• the series of vertebrae extending from the skull to the pelvis; the spine.
• "prickles of sweat broke out along her backbone"
• the chief support of a system or organization.
• "these firms are the backbone of our industrial sector"
• a high-speed, high-capacity digital connection which forms the axis of a local or wide area network.
