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 of subterranean

• underground

Examples of subterranean in a Sentence

a subterranean bunker that supposedly could withstand even an atomic blast

Recent Examples on the Web

This Pulitzer-winning neo-slave narrative reimagines the Underground Railroad as a real subterranean network, in a Sisyphean allegory that illustrates the relentless metamorphoses of white supremacy and Black resistance. — Julian Lucas, New Yorker, 22 July 2026

Call it the canary yellow uniforms in the coal mine — except the Red Sox have shot up the elevator shaft, bursting from their subterranean crypt. — Tyler Kepner, New York Times, 20 July 2026

Grant Gardner saw the limits of those profiles while managing Al Coro, Mel’s and the subterranean cocktail club Discolo in New York. — Noel Burgess, Forbes.com, 20 July 2026

As the tunnel approached Court Square, workers were spread out across the three subterranean tracks. — Evan Simko-Bednarski, New York Daily News, 19 July 2026

Word History

Etymology

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

First Known Use

1603, in the meaning defined at sense 1

Rhymes for subterranean

• romanian
• roumanian
• rumanian
• ukrainian
• cenomanian
• lithuanian
• pennsylvanian
• pomeranian
• mediterranean

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