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

That is the same theory underpinning the controversial airstrikes since September on alleged drug traffickers' boats in the Caribbean and the Pacific.

From Barron's • May 29, 2026

The profits underpinning chip companies’ stocks are a distinction from the dot-com bubble, however, when many of the biggest winners had little or no earnings.

From The Wall Street Journal • May 28, 2026

His pace and dribbling quality have always been best in class - underpinning a unique profile in the modern game.

From BBC • May 16, 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

But in the Andean past, the long, puffy bolls of South American cotton, some varieties naturally tinted pink, blue, or yellow, were the soft underpinning of Andean culture.

From "1491" by Charles C. Mann