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 of underpinning

• basis
• foundation
• bedrock
• cornerstone

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

Insiders know that the technical underpinnings of watermarking are a gambit of trade-offs, and soon, the rest of society is going to witness this with their own eyes and ears. — Lance Eliot, Forbes.com, 13 Aug. 2026

However, the political underpinnings of that panic are rarely identified and challenged. — Literary Hub, 13 Aug. 2026

Having sought to upend the global maritime order — the underpinning of the global goods trade, energy flows, food supplies, and internet communications — China now seeks the trust of smaller countries to shape the digital one. — Andy Browne, semafor.com, 4 Aug. 2026

Otherwise, the underpinnings are perfectly sorted. — Utkarsh Sood june 27, New Atlas, 27 June 2026

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