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

To me, treating the symptoms of homelessness without addressing the underlying cause feels like treating a gunshot wound with a Band-Aid. —Sarah Stella, The Conversation, 9 Oct. 2025

Courts have found that driving without a license, a misdemeanor that in Alabama carries a fine of $10 to $100, doesn’t constitute underlying recklessness for charges like manslaughter or murder. —Amy Yurkanin, ProPublica, 9 Oct. 2025

Public conversations often tend away from underlying concerns and instead toward inflammatory language. —Taylor Seely, AZCentral.com, 9 Oct. 2025

But the underlying technology will keep improving regardless of any short-term bubble, and some companies will emerge as the Googles and Amazons of the AI era. —Alyson Shontell, Fortune, 8 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