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

Transfers out and in should rely on a number of factors, including the upcoming fixtures for the outgoing and incoming players, as well as their underlying numbers. —Holly Shand, New York Times, 23 Oct. 2025

Fernando Fernandez, Unilever chief executive officer, said the outlook remained unchanged for the full year, with underlying sales growth expected to land between 3 percent and 5 percent. —Samantha Conti, Footwear News, 23 Oct. 2025

Novavax was approved for children 12 and older with an underlying condition and people over 65. —Mary Walrath-Holdridge, USA Today, 23 Oct. 2025

However, excessive and persistent thirst—a condition known as polydipsia—can reveal an underlying medical issue. —Lauren O'Connor, Health, 23 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