backbone

noun

back·​bone ˈbak-ˈbōn 

-ˌbōn

1

: spinal column, spine

2

: something that resembles a backbone: such as

a

: a chief mountain ridge, range, or system

b

: the foundation or most substantial or sturdiest part of something

c

: the longest chain of atoms or groups of atoms in a usually long molecule (such as a polymer or protein)

d

: the primary high-speed hardware and transmission lines of a telecommunications network (such as the Internet)

3

: firm and resolute character

4

: spine sense 1c

backboned

ˈbak-ˌbōnd 

adjective

Synonyms of backbone

• spine

Examples of backbone in a Sentence

She is the backbone of the family.

He showed some backbone by refusing to compromise his values.

Recent Examples on the Web

To be sure, digital undersea cables are the backbone of the world's internet and telecommunications infrastructure, enabling everything from international phone calls to financial transactions. —Sam Meredith, CNBC, 25 Feb. 2026

Both help fill the left side of the defense, along with youngster Shakir Mukhamadullin and current longtime backbone Mario Ferraro. —Eric Stephens, New York Times, 24 Feb. 2026

Days later, Russia struck again, targeting the high-voltage transmission lines that form the grid’s backbone. —Bloomberg Opinion, Twin Cities, 24 Feb. 2026

But Hopland’s pull is year-round, with an unhurried pace, a deep agricultural backbone and affordable tasting fees that feel like a time capsule from an earlier era of California. —Audrey T. Williams, Mercury News, 23 Feb. 2026

Word History

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for backbone

• alone
• atone
• bemoan
• bluestone
• breastbone
• brownstone
• capstone
• cheekbone
• condone
• curbstone
• cyclone
• dethrone

Kids Definition

backbone

noun

back·​bone -ˈbōn 

-ˌbōn

1

: the skeleton of the trunk and tail of a vertebrate that consists of a jointed series of vertebrae enclosing and protecting the spinal cord

called also spinal column

2

: the foundation or sturdiest part of something

3

: firmness of character

a coward with no backbone

backboned

-ˈbōnd 

-ˌbōnd

adjective

Medical Definition

backbone

noun

back·​bone -ˈbōn, -ˌbōn 

1

: spinal column, spine

2

: the longest chain of atoms or groups of atoms in a usually long molecule (as a polymer or protein)