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

Charred hazardous waste and large debris must be cleared by professional crews, and the underlying soil needs to be treated to remove toxic chemicals that burned into it. —Ella Nilsen, CNN, 16 Jan. 2025

The company’s underlying financials are uninspiring, but its stock price (ticker: DJT) has surged regardless since Trump won the presidential election. —Brian Barrett, WIRED, 16 Jan. 2025

And a ceasefire does nothing to address the underlying conflict that spawned the war. —Joseph Krauss, Chicago Tribune, 16 Jan. 2025

These microstructures are composed of overlapping stacks or layers of tissue, resembling the pages of a book, underlying dense, hair-like setae. —Grrlscientist, Forbes, 16 Jan. 2025

Word History

First Known Use

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

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