underpin

American  

[uhn-der-pin] / ˌʌn dərˈpɪn /

verb (used with object)

underpinned, underpinning

1. to prop up or support from below; strengthen, as by reinforcing a foundation.

2. to replace or strengthen the foundation of (a building or the like).

3. to furnish a foundation for; corroborate.

   The author's conclusions are underpinned by references to experimental findings.

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underpin British  

/ ˌʌndəˈpɪn /

verb

1. to support from beneath, esp by a prop, while avoiding damaging or weakening the superstructure

   to underpin a wall

2. to give corroboration, strength, or support to

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Etymology

Origin of underpin

First recorded in 1515–25; under- + pin

Explanation

To underpin is to justify or support the ideas behind something, the way your extensive research underpins your self-published book on ice cream trucks in the United States. Whenever you substantiate someone's claims, theories, or stories, you underpin them. A slightly different way to underpin is to form the basis or foundation of something: "A philosophy of empathy and kindness underpins all the interactions at my wonderful summer camp." This verb can also be used in a more literal way, to mean "support from below," the way the foundation of a house underpins everything that's built on top of it.

Example Sentences

Lenders are resilient in an inflationary environment without a recession, while artificial-intelligence demand should underpin tech stocks, they say.

From The Wall Street Journal • May 25, 2026

"The chemicals and ceramics industries underpin our economic resilience and support skilled jobs across the UK," said chancellor Rachel Reeves.

From BBC • May 21, 2026

And the supply/demand imbalance is continuing to underpin oil prices.

From MarketWatch • May 21, 2026

The budgetary equation is all the more fraught because inflation is likely to push central banks to raise their benchmark rates, which underpin all interest rates, Juvyns said.

From Barron's • May 20, 2026

The AIG FP traders present were shocked by how little thought or analysis seemed to underpin the subprime mortgage machine: It was simply a bet that home prices would never fall.

From "The Big Short" by Michael Lewis