subterranean

American  

[suhb-tuh-rey-nee-uhn] / ˌsʌb təˈreɪ ni ən /

adjective

1. existing, situated, or operating below the surface of the earth; underground.

2. existing or operating out of sight or secretly; hidden or secret.

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noun

1. a person or thing that is subterranean.

2. a subterrane.

subterranean British  

/ ˌsʌbtəˈreɪnɪən /

adjective

1. Also: subterraneous.   subterrestrial.  situated, living, or operating below the surface of the earth

2. existing or operating in concealment

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Other Word Forms

• subterraneanly
  adverb
• subterraneously
  adverb

Etymology

Origin of subterranean

1595–1605; < Latin subterrāne ( us ) ( see subterrane) + -an

Explanation

Subterranean is an adjective that describes something just below what can be seen, like the subterranean jealousy you hide under a smile and kind words for the actor who got the part you wanted. Subterranean feelings and intentions are those you keep "on the down low." In fact, real things that are subterranean really are down low — underground, in fact. A subterranean worm lives under the earth's surface. A subterranean lair is a secret hideout dug under the dirt — or maybe it's just your basement. The word comes from the Latin subterraneus, from sub meaning "under" and terra meaning "earth."

Example Sentences

See Examples For:

subterranean

Experts estimate that the subterranean complex reaches 300 to 450 feet deep beneath solid rock, with enough room to accommodate several nuclear-related facilities.

From The Wall Street Journal ● Jul. 21, 2026

“I had descended into the strange subterranean structures of aging, almost as a way to avoid the contemporary world … ,” she writes.

From Los Angeles Times ● Jul. 20, 2026

The Justice Department says 99 subterranean passages have been discovered in the Southern District of California since 1993.

From Barron's ● Jun. 2, 2026

"It's been successfully used on subterranean termites, which are also important structural pests," Choe said.

From Science Daily ● May 9, 2026

With subterranean rumblings Queenie jogged slowly down the drive and turned into the street, where Luster exhorted her into a gait resembling a prolonged and suspended fall in a forward direction.

From "The Sound and the Fury" by William Faulkner