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

The investment comes as Helix seeks to address growing competition in the AI infrastructure market by targeting both data center deployment and the underlying power infrastructure needed to support it. — Lim Hui Jie, CNBC, 29 Sep. 2026

The problem arises when organizations become so focused on moving an indicator that people begin optimizing the number rather than the underlying condition the number was supposed to represent. — Janita Pannu, Forbes.com, 29 Sep. 2026

His attorneys contend that applying the money-laundering guidelines produces a punishment wildly disproportionate to the underlying offense and point to substantially shorter sentences in other foreign-agent cases. — Antonio María Delgado, Miami Herald, 29 Sep. 2026

The see-through, art museum-worthy environment at Prada spoke to one of the week’s underlying trends in transparency. — Samantha Conti, Footwear News, 28 Sep. 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