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

After the nation’s July 4 celebration, workers began draining and repairing the pool to address the underlying problems. — David Zimmermann, The Washington Examiner, 31 July 2026

For instance, finance professor James Choi, who led the Honor Committee investigating the case, emailed Rignol multiple times looking for the underlying file Rignol had used to draft his exam answers. — Nate Anderson, ArsTechnica, 31 July 2026

That reading turns a question of building shape into a fresh environmental question, years after the underlying growth/density was studied and approved. — Zack Defazio Farrell, San Diego Union-Tribune, 31 July 2026

But the underlying geographic picture pointed to just where the brand’s top clients are today. — Tianwei Zhang, Footwear News, 31 July 2026

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