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

Green thinking underpins every practice at Hotel Maria - from the energy-efficient lighting right through to recycling programs. —Condé Nast, Condé Nast Traveler, 17 Mar. 2026

Your actions underpin your identity. —Tarot.com, New York Daily News, 15 Mar. 2026

Missing from that tally are fees paid to four law firms whose work underpinned the removal process. —Ryan MacAsero, Mercury News, 15 Mar. 2026

In January, the Defense Department withdrew a federal regulation that underpinned the mandate, according to Stars and Stripes. —Maria Aspan, NPR, 14 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