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

The star business underpinning the estimated $1.8 trillion valuation is Starlink, SpaceX’s space-based broadband product.

From Barron's • Jun. 7, 2026

Indeed, strong corporate earnings and upbeat forecasts for the year ahead are underpinning the advance.

From The Wall Street Journal • Jun. 1, 2026

Yet "the talent, capital, and supply chains underpinning the field are deeply intertwined across the United States and China," said Grace Shao, a China AI analyst and author of the AI Proem newsletter.

From Barron's • May 13, 2026

Chongqing leads the country in car manufacturing, underpinning China's position as the world's largest car-maker.

From BBC • May 12, 2026

In the recognition by Pythagoras and Plato that the Cosmos is knowable, that there is a mathematical underpinning to nature, they greatly advanced the cause of science.

From "Cosmos" by Carl Sagan