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

First and foremost, red diesel originates from the same underlying US diesel pool and does not represent net additive refining capacity. — CNBC, 7 Oct. 2026

Advertisement Some analysts, however, questioned how much relief the waiver can deliver without addressing underlying diesel supply constraints. — Miranda Jeyaretnam, Time, 6 Oct. 2026

Margins shrink, investment capacity falls and businesses have fewer resources to innovate or improve the underlying infrastructure. — Sanjay Ghare, Forbes.com, 6 Oct. 2026

The idea is rather simple; by considering many different climate models instead of just one, the underlying uncertainty can be taken into account when forecasting out weeks or months in advance. — Sean MacAday, Sacbee.com, 5 Oct. 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