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

Beren Cross What the data says Leeds’ three victories have come against sides currently in the bottom seven, but their underlying numbers offer plenty of reason for optimism. —Chris Weatherspoon, New York Times, 31 Oct. 2025

To cement the point, Nvidia, a maker of the advanced computer chips underlying the AI boom, yesterday became the first company in history to be worth $5 trillion. —Matteo Wong, The Atlantic, 30 Oct. 2025

Such brands are generally aligned in their use of organic natural fibers, limited inclusion of synthetics and underlying wellness messaging. —Sophie Benson, Vogue, 30 Oct. 2025

Beyond cognitive benefits, lion’s mane also appears to have antioxidant and anti-inflammatory effects, which may help reduce oxidative stress – an underlying contributor to many chronic diseases. —Daryl Austin, USA Today, 29 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