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

Even the most altruistic acts have some psychological or emotional underpinning.

From MarketWatch • Jun. 3, 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

The thesis is misnamed, because, as it is usually formulated, Duhem did not hold it and Quine abandoned it, but it is the fundamental conceptual underpinning of much modern history and philosophy of science.

From "The Invention of Science" by David Wootton