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

More specifically, insects are invertebrates (animals without backbones) and are part of the arthropod phylum, which also includes spiders, crabs, and centipedes. — Encyclopedia Britannica, 14 Aug. 2026

This milestone shows that utility-scale battery storage is no longer experimental, but an essential backbone supporting the modern electric grid. — Mrigakshi Dixit, Interesting Engineering, 14 Aug. 2026

Richardson says the backbone of this lawsuit is tied to a 2024 ordinance that requires landlords to keep elevators working or, if they are broken, offer temporary housing to residents who can't use the stairs. — CBS News, 13 Aug. 2026

Oral PrEP is still the backbone of prevention While lenacapavir is the new shiny breakthrough, oral PrEP remains the mainstay of prevention. — Michal Ruprecht, NPR, 13 Aug. 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)