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

A number of rate setters were already prepared to back a rise in borrowing costs at their April meeting, the European Central Bank said Thursday, likely underpinning expectations for a move next month.

From The Wall Street Journal • May 28, 2026

The business logic underpinning all of it is a subscription model that distinguishes the Times sharply from traditional game companies.

From Barron's • May 16, 2026

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

From BBC • May 12, 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