underlying

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

Synonyms

• basic
• rudimentary
• elementary
• fundamental
• introductory

Examples of underlying in a Sentence

the ocean and the underlying rock

the underlying differences between democracy and dictatorship

Recent Examples on the Web

Unlike cash, bonds, property or stocks, Bitcoin does not entitle the owner to any underlying asset, interest, or cash flow. —Jim Edwards, Fortune, 7 Oct. 2025

Men’s products always come out with a slight, underlying red tone. —The Editors, Robb Report, 4 Oct. 2025

Factors such as fitness level, underlying health conditions, and age can significantly affect a person's ability to meet a high step count. —Chelsea Rae Bourgeois, Health, 2 Oct. 2025

This model aligns well with the new data and points to a negative underlying cosmological constant. —Sujita Sinha, Interesting Engineering, 2 Oct. 2025

Word History

First Known Use

1611, in the meaning defined at sense 1a

Rhymes for underlying

• amplifying
• beautifying
• certifying
• clarifying
• classifying
• codifying
• crucifying
• edifying
• falsifying
• fortifying
• glorifying
• gratifying

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