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

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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

Within two years, an ingenious tunnel complex was constructed, with arched ceilings and thick walls, and zigzag subterranean pathways to better absorb bomb blasts. — Maureen O'Hare, CNN Money, 26 Sep. 2026

Lielle, chef Marcus Jernmark’s subterranean Westside restaurant, is one of Los Angeles’ most exciting fine-dining debuts, pairing Scandinavian instincts with California sensibility. — Bill Addison, Los Angeles Times, 24 Sep. 2026

The subterranean expansion will be constructed beneath Plaza Perú, the public park that neighbors the museum, and will roughly double the museum’s current exhibition space. — News Desk, Artforum, 23 Sep. 2026

Previous seasons saw Vernon curate the subterranean room into messy domestic tableaux, with pieces nestled among scenes of dinner parties and unfinished musical manuscripts—the detritus of a chaotic creative process. — Anna Cafolla, Vogue, 21 Sep. 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