underlying

1 of 2

adjective

un·​der·​ly·​ing ˌən-dər-ˈlī-iŋ 

1

a

: lying beneath or below

the underlying rock is shale

b

: basic, fundamental

an investigation of the underlying issues

2

: evident only on close inspection : implicit

3

: anterior and prior in claim

underlying mortgage

4

: of or being present in deep structure

underlying word order

underlying

2 of 2

present participle of underlie

Synonyms of underlying

Adjective

• basic
• rudimentary
• elementary
• fundamental
• introductory

Examples of underlying in a Sentence

Adjective

the ocean and the underlying rock

the underlying differences between democracy and dictatorship

Recent Examples on the Web

Adjective

Yun also emphasized underlying factors that might keep mortgage rates elevated for homebuyers over a longer period of time. — Zach Halaschak, The Washington Examiner, 5 Oct. 2026

There’s a place for topical solutions and other hair loss treatments (including minoxidil), but blood tests are the first step to uncovering the underlying cause of shedding. — Maggie Ryan, Flow Space, 2 Oct. 2026

Choosing the right software partnership matters, especially as underlying business models shift. — Salvatore Lombardo, Forbes.com, 2 Oct. 2026

Different sensors and computing hardware can support the same underlying architecture. — Aamir Khollam, Interesting Engineering, 1 Oct. 2026

Word History

First Known Use

Adjective

1611, in the meaning defined at sense 1a

Rhymes for underlying

• applying
• belying
• complying
• decrying
• defying
• denying
• implying
• outlying
• relying
• replying
• supplying
• undying

Kids Definition

underlying

adjective

un·​der·​ly·​ing ˌən-dər-ˌlī-iŋ 

1

: lying under or below

the underlying rock

2

: fundamental entry 1 sense 1

Medical Definition

underlying

adjective

un·​der·​ly·​ing -ˌlī-iŋ 

: serving as a basis or cause (as of secondary symptoms)

the underlying brain malformation that caused the hydrocephalus

—R. M. Henig