underlie

verb

un·​der·​lie ˌən-dər-ˈlī 

underlay ˌən-dər-ˈlā  ; underlain ˌən-dər-ˈlān  ; underlying ˌən-dər-ˈlī-iŋ 

transitive verb

1

: to lie or be situated under

2

: to be at the basis of : form the foundation of : support

ideas underlying the revolution

3

: to exist as a claim or security superior and prior to (another)

4

archaic : to be subject or amenable to

Examples of underlie in a Sentence

A tile floor underlies the rug.

The river is underlain by limestone.

We discussed the principles that underlay their methods.

A theme of revenge underlies much of her writing.

Recent Examples on the Web

Soil acidity also comes from what is called the parent material — the bedrock that underlies the soil. —Paul Cappiello, Louisville Courier Journal, 3 Oct. 2025

Rowe also cited remarks covered by Fortune from Nvidia CEO Jensen Huang about the need for blue-collar workers to power the data-center infrastructure underlying the AI boom. —Nick Lichtenberg, Fortune, 2 Oct. 2025

No one can stop the Rams' third-year receiver, and Derrik Klassen explains the stats underlying Nacua's greatness. —Jacob Robinson, New York Times, 1 Oct. 2025

His work also touches on nostalgia — an underlying concern that what Puerto Ricans are today could be lost tomorrow, as gentrification and an influx of outsiders threatens to erase parts of the culture. —Cata Balzano, HollywoodReporter, 1 Oct. 2025

Word History

First Known Use

before the 12th century, in the meaning defined at sense 4

Rhymes for underlie

• apply
• awry
• belie
• bely
• bigeye
• bonsai
• buckeye
• comply
• coxae
• decry
• defy
• deny

Kids Definition

underlie

verb

un·​der·​lie ˌən-dər-ˈlī 

underlay -ˈlā  ; underlain -ˈlān  ; underlying -ˈlī-iŋ 

1

: to lie or be located under

2

: to form the foundation of : support

ideas underlying the revolt