underpinning

American  

[uhn-der-pin-ing] / ˈʌn dərˌpɪn ɪŋ /

noun

1. a system of supports beneath a wall or the like.

2. Often underpinnings. a foundation or basis.

   to uncover the emotional underpinnings of an illness.

3. Informal. underpinnings,

   1. underwear, especially women's underwear.

   2. the legs.

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underpinning British  

/ ˈʌndəˌpɪnɪŋ /

noun

1. a structure of masonry, concrete, etc, placed beneath a wall to provide support

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Etymology

Origin of underpinning

First recorded in 1480–90; under + pin + -ing ¹

Example Sentences

Yet with AI spending estimated at $700 billion this year, and projected to grow over the next few years, it’s a “very powerful engine” underpinning the U.S. economy, Hughey said.

From MarketWatch • May 7, 2026

“The fundamentals underpinning our markets remain strong, even if recent macroeconomic and geopolitical developments have increased uncertainty,” Chief Executive Olivier Blum said.

From The Wall Street Journal • Apr. 30, 2026

It not only generates headlines and moments that travel far beyond the Empire Polo Club, but serves as a microcosm of the attention economy underpinning the broader media and entertainment landscape.

From Los Angeles Times • Apr. 26, 2026

And these memos lay bare the extent to which the work product underpinning these decisions is often half-hearted and vibes-based; animated more by grievance and hurt feelings than neutral legal rules.

From Slate • Apr. 21, 2026

Toby crying, huddled behind the cracked underpinning of the trailer.

From "We'll Fly Away" by Bryan Bliss