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

Epigenetic changes are modifications of gene expression that don’t change the underlying DNA sequence. —Noah Lyons, San Diego Union-Tribune, 6 Apr. 2026

Warson said the underlying infrastructure for physical AI has finally caught up with real-life use cases. —Catherina Gioino, Fortune, 6 Apr. 2026

Keep in mind that this is private-sector, objective data, based on measurable real-world conditions, unvarnished by politics or anyone’s underlying agenda. —Edward Lotterman, Twin Cities, 5 Apr. 2026

The transition from wheels to weapons and back again is achievable in part because many of the underlying skills are highly transferable, according to experts. —Sam Meredith,joseph Wilkins, CNBC, 5 Apr. 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