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

Experts predict the face of university research could be permanently changed, affecting work on treatments for cancer, Alzheimer's, and diabetes, among other conditions, along with studies on the underpinnings of disease. —Erica Pandey, Axios, 21 Mar. 2025

But even despite their lush surfaces, Eversley’s sculptures stand apart from nearly all other Finish Fetish art because of their scientific underpinning. —Alex Greenberger, ARTnews.com, 18 Mar. 2025

State government had — and still has — very little ability to build housing or ameliorate the economic and societal underpinnings of homelessness. —Dan Walters, The Mercury News, 3 Mar. 2025

The order was seen as the underpinning of the federal government’s commitment to affirmative action. —Michael D. Shear, New York Times, 25 Jan. 2025

Word History

First Known Use

15th century, in the meaning defined at sense 1

Rhymes for underpinning

• beginning
• binning
• dinning
• ginning
• grinning
• inning
• pinning
• sinning
• skinning
• spinning
• thinning
• tinning

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