backbone

• back bone

From Middle English bakbon, bakebon, bac-bon; equivalent to back +‎ bone. Compare the semantically analogous English ridgebone.

• (UK) IPA^(key): /ˈbækˌbəʊn/
• (US) IPA^(key): /ˈbækˌboʊn/

• Audio (US):

  (file)

• Rhymes: -ækbəʊn, -ækboʊn

backbone (countable and uncountable, plural backbones)

1. (countable) The series of vertebrae, separated by disks, that encloses and protects the spinal cord, and runs down the middle of the back in vertebrate animals.
2. (countable, figuratively) Any fundamental support, structure, or infrastructure.

   Before automobiles, railroads were a backbone of commerce.

   • 1945 November and December, H. C. Casserley, “Random Reflections on British Locomotive Types—1”, in Railway Magazine, page 320:

     Undoubtedly it can be said that the humble 0-6-0 has been the backbone for general service, or general utility on British railways right from their earliest days, and is likely to remain so.

   • 1959 April, P. Ransome-Wallis, “The Southern in Trouble on the Kent Coast”, in Trains Illustrated, London: Ian Allan Publishing, →ISSN, →OCLC, page 212:

     With little regular employment available in East Kent the backbone of the Kent Coast passenger traffic is therefore the commuters, the not inconsiderable numbers of people who travel each day to their work in Faversham, Sittingbourne, the Medway Towns and most of all, London.

   • 1980, AA Book of British Villages, Drive Publications Ltd, page 220, about Hambledon, Hants:

     East [Street] and West Street form a single thoroughfare running as a backbone through the village, flanked by neat, painted cottages of predominantly 18th-century brick.

   • 1989 December 10, John Zeh, “AIDS Groups' Execs Arrested In D.C.”, in Gay Community News, volume 17, number 22, page 1:

     The San Francisco AIDS Foundation (SFAF) and other community-based organizations that "provide backbone and leadership" in AIDS services are "reeling under the impact of growing case loads," said Pat Christen, SFAF's new director.

   • 2025 April 17, “Provider Backbone Bridging (PBB) and EVPN Integration Overview”, in Juniper Networks‎^[1], archived from the original on 1 July 2025:

     When operating on customer MAC (C-MAC) and service MAC (S-MAC) addresses, PBB uses a new backbone MAC (B-MAC) address. The B-MAC address is added at the edge of the PBB network, that is administered by a carrier VPN or a carrier-of-carriers VPN.

3. (uncountable, figuratively) Courage, fortitude, or strength.

   He would make a good manager, if he had a little more backbone.

   • 1899 February, Joseph Conrad, “The Heart of Darkness”, in Blackwood’s Edinburgh Magazine, volume CLXV, number M, New York, N.Y.: The Leonard Scott Publishing Company, […], →OCLC, part I, page 207:

     His appearance was certainly that of a hairdresser's dummy; but in the great demoralization of the land he kept up his appearance. That's backbone. His starched collars and got-up shirt-fronts were achievements of character. He had been out nearly three years; and, later, I could not help asking him how he managed to sport such linen.

• spine
• spinal column
• vertebral column
• See also Thesaurus:backbone