underpinning

noun

un·​der·​pin·​ning ˈən-dər-ˌpi-niŋ 

1

: the material and construction (such as a foundation) used for support of a structure

2

: something that serves as a foundation : basis, support

—often used in plural

the philosophical underpinnings of educational methods

3

: underwear

—usually used in plural

4

: a person's legs

—usually used in plural

Synonyms

• base
• basis
• bedrock
• bottom
• cornerstone
• footing
• foundation
• ground
• groundwork
• keystone
• root
• warp
• warp and woof

Examples of underpinning in a Sentence

the underpinnings of the theory have recently been called into question

the underpinnings of the bridge were seriously damaged in the collision

Recent Examples on the Web

These measures should be coupled with a broader recommitment to political and civil rights for all, the underpinnings of a fully participatory and representative democracy. —Linda Robinson, Foreign Affairs, 3 July 2024

Her nonfiction book delves into the psychological underpinnings that make people so vulnerable to cons. —Vanessa Armstrong, The Atlantic, 17 June 2024

After a seven-year run as a tweener — built on a smaller platform but still offering three rows of seats — the 2024 Acadia is based on the same underpinnings as the Chevrolet Traverse and Buick Enclave, both of which are also new this year. —Mark Phelan, Detroit Free Press, 13 June 2024

For model-year 2024, the underpinnings remain the same, although our test car is an all-wheel-drive version. —Jonathan M. Gitlin, Ars Technica, 30 May 2024

Word History

First Known Use

15th century, in the meaning defined at sense 1

Kids Definition

underpinning

noun

un·​der·​pin·​ning ˈən-dər-ˌpin-iŋ 

1

: the foundation used for support of a structure

2

: prop entry 1, support

3

: a person's legs

—usually used in plural