backbone

/ˈbækbəʊn/ noun [C, usually singular]

Definition

the backbone (of sth) › the most important part of something: Small businesses are truly the backbone of the economy. Imaginative ideas may form the backbone of your progress in the future.

› COMMUNICATIONS, IT the system of equipment and connections that allows communication at high speeds over long distances: The company runs the biggest internet backbone in the US, carrying about 37% of data traffic.

(Definition of backbone noun from the Cambridge Business English Dictionary © Cambridge University Press)

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