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

At the same time, however, Bush sought to address some of the underlying issues — the racist history of the LAPD, chief among them — that festered for decades before exploding into molten rage. —Mark Z. Barabak, Los Angeles Times, 9 June 2025

The aerospace giant's stock performance reflects this pattern: initial volatility followed by sustained gains as markets recognize the underlying strength of the business model and the temporary nature of most trade disruptions. —Robert Daugherty, Forbes.com, 7 June 2025

The underlying issue in the case involves whether DOGE is subject to the Freedom of Information Act. —Melissa Quinn, CBS News, 6 June 2025

Authorities are investigating whether Soliman has any underlying mental health issues, a source familiar with the investigation previously told CNN. —Jeremy Harlan, CNN Money, 6 June 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