subterranean

adjective

sub·​ter·​ra·​nean ˌsəb-tə-ˈrā-nē-ən 

-nyən

variants or less commonly subterraneous

ˌsəb-tə-ˈrā-nē-əs 

-nyəs

1

: being, lying, or operating under the surface of the earth

2

: existing or working in secret : hidden

a subterranean network of criminals

subterraneanly adverb

or less commonly subterraneously

Did you know?

Go Underground With Subterranean

A tunnel is a subterranean road or pathway, and a subway is a subterranean railway. The subterranean vaults at Fort Knox hold billions of dollars of gold reserves. Subterranean reservoirs called aquifers are tapped for water; in places where the pressure on the subterranean water is great enough, a hole drilled in the ground will bring it bubbling to the surface.

Synonyms

• belowground
• subsurface
• underground

Examples of subterranean in a Sentence

a subterranean bunker that supposedly could withstand even an atomic blast

Recent Examples on the Web

Farrow & Ball’s Cooking Apple Green on the walls complements the floors, which are painted in the company’s warm Picture Gallery Red—a popular hue for subterranean floors of the home’s era. —David Foxley, Architectural Digest, 20 Nov. 2024

The cave is home to a subterranean lake that is perfectly lit throughout the day thanks to a hole in the cave's ceiling. —Stacey Leasca, Travel + Leisure, 5 Nov. 2024

Round out the evening with a nightcap at the subterranean tavern–then head to bed, an elevator ride away. —Brittany Anas, The Denver Post, 30 Oct. 2024

Celebrated monster-suit actor Doug Jones portrays the fiend, as well as the long-limbed Faun who leads our young hero (Ivana Baquero) into a subterranean world of magic and danger. —Katie Rife, EW.com, 18 Oct. 2024

Word History

Etymology

Latin subterraneus, from sub- + terra earth — more at thirst

First Known Use

1603, in the meaning defined at sense 1

Kids Definition

subterranean

adjective

sub·​ter·​ra·​nean ˌsəb-tə-ˈrā-nē-ən 

-nyən

1

: being, lying, or operating under the surface of the earth

2

: existing or working in secret : hidden