underpin

American  

[uhn-der-pin] / ˌʌn dərˈpɪn /

verb (used with object)

• underpins,
  present (3rd person singular)
• underpinned,
  past participle,  past
• underpinning
  present participle

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.

---

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

---

Other Word Forms

Inflected Forms

Participles

• underpinning
  present
• underpinned
  past

Conjugated Forms

Present

• underpin
  simple
• underpins
  simple
• have underpinned
  perfect
• has underpinned
  perfect
• am underpinning
  progressive
• are underpinning
  progressive
• is underpinning
  progressive
• have been underpinning
  perfect progressive
• has been underpinning
  perfect progressive

Past

• underpinned
  simple
• had underpinned
  perfect
• was underpinning
  progressive
• were underpinning
  progressive
• had been underpinning
  perfect progressive

Future

• will underpin
  simple
• will have underpinned
  perfect
• will be underpinning
  progressive
• will have been underpinning
  perfect progressive

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

See Examples For:

underpin underpins underpinned underpinning

Treasury yields, which underpin the rates on new mortgages, auto loans and several other forms of consumer credit, have climbed appreciably since early 2022.

From MarketWatch ● Sep. 16, 2026

He points out that the recent observations that underpin these estimates cover a relatively short period.

From BBC ● Sep. 8, 2026

Household spending in Canada has remained relatively resilient, helping underpin an economy that has shown signs of rebounding following back-to-back quarterly contractions.

From The Wall Street Journal ● Aug. 27, 2026

“ByteDance respects the intellectual property rights that underpin creative industries around the world, and we believe responsible innovation in AI goes hand in hand with meaningful protections for rightsholders,” ByteDance’s Rogovin said in the statement.

From Los Angeles Times ● Aug. 17, 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

In an initial report, external, Nats said the defect happened in the system which "underpins the management of UK airspace".

From BBC ● Sep. 18, 2026

The pact underpins $1.6tn in North American trade.

From BBC ● Aug. 24, 2026

Finally, shifting financing would weaken the sense of shared responsibility that underpins Medicare.

From MarketWatch ● Aug. 24, 2026

Large language models are the technology that underpins chatbots and other AI tools by crunching vast amounts of digital data.

From Barron's ● Aug. 10, 2026

It is quiet, and when the belling tower strikes the late hour, it doesn’t break the silence so much as it underpins it.

From "The Name of the Wind" by Patrick Rothfuss

A major reason homeownership underpinned wealth for previous generations is that a mortgage can function as a sort of forced savings account.

From MarketWatch ● Sep. 16, 2026

Treasury Secretary Scott Bessent have underpinned the recovery.

From The Wall Street Journal ● Sep. 10, 2026

Delap's struggles at Chelsea have been underpinned by three managerial changes and hamstring and shoulder injuries, but also difficulties adjusting to a different gameplan.

From BBC ● Aug. 27, 2026

Analysts at Citi said they expect a “robust” 30 trillion won per quarter dividend to be sustained, backed by the secular memory market outlook that’s underpinned by long-term agreements.

From MarketWatch ● Aug. 24, 2026

It simply interested him—greatly—how all the cultures of Zeru were underpinned by the same story.

From "Strange the Dreamer" by Laini Taylor

This sets up Shopify to benefit from “the infrastructure layer underpinning AI-driven commerce rather than being at risk of displacement.”

From The Wall Street Journal ● Sep. 18, 2026

It views data centres as underpinning public services and crucial to attract investment and allow Britain to compete in the global economy.

From BBC ● Sep. 15, 2026

For Farber, the "overarching ecosystem" in Munich and surrounding Bavaria state is underpinning the growth of defence startups.

From Barron's ● Sep. 1, 2026

One of the most common assumptions underpinning the “Gen Z doesn’t drink” narrative is that young adults simply don’t want to go out anymore.

From Salon ● Aug. 15, 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