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
- belowground
- subsurface
- underground
See all Synonyms & Antonyms 
Example Sentences
a subterranean bunker that supposedly could withstand even an atomic blast
Recent Examples on the Web This lowered the agency’s public reputation to a subterranean level. 
Michael Hiltzik, Los Angeles Times, 10 Aug. 2022 Because of their lack of light and subterranean location, most maintain a constant temperature around 50 degrees — perfect for exploring on a hot summer day. Chelsey Lewis, Journal Sentinel, 5 Aug. 2022 Oil, commonly known as petroleum, is a subterranean liquid mixture that, when refined, may be used to create gasoline, diesel and several other products. Tunde Ajala, Forbes, 10 Aug. 2022 Its brutalist concrete exterior gives way to a subterranean lobby with black leather furniture and tranquil water features. Katie Lockhart, House Beautiful, 5 Aug. 2022 With a bedrock of sandstone and shale, two minerals less water soluble than limestone, the area didn’t lend itself to the familiar stalactites and stalagmites of other subterranean tunnels. Emily Pennington, Outside Online, 29 July 2022 Mariupol officials said in mid-April that as many as 1,000 civilians were also hiding in the subterranean network. Reis Thebault, Washington Post, 17 May 2022 In the subterranean world where many of those remaining in the city spend their nights, an overture of snores could be heard at a subway station on the city’s western side. Los Angeles Times, 25 Mar. 2022 Such subterranean pressures are, as yet, hard to substantiate. Fred Weir, The Christian Science Monitor, 12 July 2022 See More
Michael Hiltzik, Los Angeles Times, 10 Aug. 2022 Because of their lack of light and subterranean location, most maintain a constant temperature around 50 degrees — perfect for exploring on a hot summer day. Chelsey Lewis, Journal Sentinel, 5 Aug. 2022 Oil, commonly known as petroleum, is a subterranean liquid mixture that, when refined, may be used to create gasoline, diesel and several other products. Tunde Ajala, Forbes, 10 Aug. 2022 Its brutalist concrete exterior gives way to a subterranean lobby with black leather furniture and tranquil water features. Katie Lockhart, House Beautiful, 5 Aug. 2022 With a bedrock of sandstone and shale, two minerals less water soluble than limestone, the area didn’t lend itself to the familiar stalactites and stalagmites of other subterranean tunnels. Emily Pennington, Outside Online, 29 July 2022 Mariupol officials said in mid-April that as many as 1,000 civilians were also hiding in the subterranean network. Reis Thebault, Washington Post, 17 May 2022 In the subterranean world where many of those remaining in the city spend their nights, an overture of snores could be heard at a subway station on the city’s western side. Los Angeles Times, 25 Mar. 2022 Such subterranean pressures are, as yet, hard to substantiate. Fred Weir, The Christian Science Monitor, 12 July 2022 See More 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
: being, lying, or operating under the surface of the earth
a subterranean lake
subterranean
adjective
as in underground
being, situated, or operating beneath the surface of the earth a subterranean bunker that supposedly could withstand even an atomic blast Synonyms & Similar Words
Relevance
- underground
- subsurface
- belowground
Antonyms & Near Antonyms
- surface
- aboveground