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

• abecedarian
• basal
• basic
• beginning
• elemental
• elementary
• essential
• fundamental
• introductory
• meat-and-potatoes
• rudimental
• rudimentary

Examples of underlying in a Sentence

the ocean and the underlying rock

the underlying differences between democracy and dictatorship

Recent Examples on the Web

There doesn’t have to be a grand underlying purpose that guides you along your breathing living journey. —Lance Eliot, Forbes, 21 Dec. 2024

Rather, those little white or yellowish crumbs could be signs of a few different issues that deserve your attention, like dry skin craving moisture, for example, or an underlying condition leading to irritation or inflammation. —Jenna Ryu, SELF, 20 Dec. 2024

The San Xavier District, like Tucson, benefits from the intermittent flows and underlying aquifer along the Santa Cruz River, which lies downslope of Copper World. —Brandon Loomis, The Arizona Republic, 19 Dec. 2024

The patient, a Louisiana resident who is over the age of 65 and has underlying medical conditions, is in the hospital with severe respiratory illness and is in critical condition. —Yasmin Tayag, The Atlantic, 19 Dec. 2024

Word History

First Known Use

1611, in the meaning defined at sense 1a

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