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

That was the truth underlying everything. —Literary Hub, 7 Nov. 2025

Without addressing these underlying drivers, and most importantly, rising hospital prices, then insurance will be expensive, whether it's paid for by patients or subsidized by taxpayers. —Jasmine Laws, MSNBC Newsweek, 6 Nov. 2025

According to Bloomberg, after testing models from Google, OpenAI, and Anthropic, Apple has chosen Google’s technology to help rebuild Siri’s underlying system. —Sharon Goldman, Fortune, 6 Nov. 2025

For centuries the Maya have understood how the underlying properties of this corner of the world help heal and strengthen the mind and body. —Robb Report Studio, Robb Report, 5 Nov. 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