underpin

verb

un·​der·​pin ˌən-dər-ˈpin 

underpinned; underpinning; underpins

transitive verb

1

: support, substantiate

underpin a thesis with evidence

2

: to form part of, strengthen, or replace the foundation of

underpin a structure

underpin a sagging building

Synonyms of underpin

• sustain
• carry
• support
• bolster

Examples of underpin in a Sentence

a wall underpinned by metal beams

the central beliefs that underpin a free society

Recent Examples on the Web

Lesotho, briefly hit with steep US tariffs last year, still faces uncertainty over the future of AGOA, the preferential US-Africa trade pact that underpins much of its export economy. —Yinka Adegoke, semafor.com, 9 Jan. 2026

The same deep learning technology that underpins ChatGPT can be used to teach the robots how to walk, use a hand or fold laundry. —Kif Leswing, CNBC, 9 Jan. 2026

Advertisement But Kedrosky is deeply worried about the financial structures underpinning the industry. —Andrew R. Chow, Time, 9 Jan. 2026

Molinaroli’s strategy sees philanthropy as a mechanism to strengthen the talent infrastructure that underpins economic growth. —Connie Etemadi, Charlotte Observer, 7 Jan. 2026

Word History

First Known Use

1522, in the meaning defined at sense 1

Rhymes for underpin

• aneurin
• crystallin
• eosin
• mandolin
• porphyrin
• violin
• akin
• auxin
• buckskin
• chagrin
• deerskin
• foreskin

Kids Definition

underpin

verb

un·​der·​pin -ˈpin 

1

: to give support to

underpin an argument with evidence

2

: to form part of, strengthen, or replace the foundation of

underpin a structure