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

The commercial shipping system uses a different implementation of the underlying idea. — Bojan Stojkovski, Interesting Engineering, 9 Nov. 2026

The underlying message is that if you’re vaccinated, you’re protected. — Rebecca Smullin Dawson, The Conversation, 6 Nov. 2026

Indeed, there are underlying signs that many Americans are struggling in their job searches. — Lauren Kaori Gurley, Washington Post, 6 Nov. 2026

Our community is dying; there’s an underlying sense of desperation, grief and pride that can both protect and suffocate out of a need to survive – this film is ultimately a love letter to us, with a sense of knowing. — Georg Szalai, HollywoodReporter, 5 Nov. 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