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

The Farizon Super Van (SV) underpinning this camper does not, making for a particularly large, breezy entry from the side. —New Atlas, 30 Mar. 2026

Critical minerals underpin the global energy transition, digital infrastructure, and defence capabilities. —Interesting Engineering, 30 Mar. 2026

But the forces being deployed are light infantry, units that lack the large armored vehicles, including tanks, that typically underpin sustained ground offensives. —Chris Boccia, ABC News, 27 Mar. 2026

Big bets worth hundreds of billions Amazon’s monolithic data centers and millions of miles of fiber optic cables underpin the internet. —Lisa Eadicicco, CNN Money, 27 Mar. 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