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

Hitchcock’s point-of-view shots evoke characters looking at the world with yearning and horror, guilt and responsibility, and those are also the emotional underpinnings of Soderbergh’s movie. —Richard Brody, The New Yorker, 17 Jan. 2025

But there will be a need for underpinning that peace and the underpinning of Ukraine's security, and that will require a real, physical commitment. —John Mac Ghlionn, Newsweek, 14 Jan. 2025

This perspective invites us to consider the psychological underpinnings of our dating preferences. —Mark Travers, Forbes, 10 Jan. 2025

New York City’s environment offers additional complexities, with obstacles such as train stations making normal underpinning inaccessible. —William Mullane, USA TODAY, 2 Nov. 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