subterranean
Beneath the surface
Subterranean describes something existing, occurring, or operating beneath the earth's surface.
A subterranean cave or subterranean river lies underground.
The word extends to figurative uses suggesting things that are hidden or secret: subterranean movements or subterranean currents of discontent operate out of public view.
The term carries slightly more literary or formal weight than its near-synonym underground.
Large natural underground chamber
- grottoSmall scenic cavern
- caveUnderground hollow in rock
- stalactiteHanging cave mineral deposit
- stalagmiteUpward-growing cave deposit
speleology · spelunker · caving · karst · sinkhole · dripstone · limestone · catacombs
Made invisible deliberately
- buriedPlaced beneath earth
- secretConcealed information
- covertIntentionally concealed
- clandestineConcealed from authorities
beneath · below · depths · unseen · obscured · underworld · shadowy · cryptic
Act of unearthing
- digUnearth by shoveling
- tombUnderground chamber for remains
- artifactsHuman-made historical objects
- stratigraphyStudy of rock layers
trowel · catacombs · neolithic · ruins · burial · ossuary · necropolis · tumulus
Narrow vertical passage
- tunnelEnclosed underground route
- oreMetal-bearing rock
- coalCombustible sedimentary rock
- excavationAct of unearthing
drill · vein · deposit · quarry · miner · pickaxe · dynamite · blasting
Underground drainage pipe
- subwayUnderground transit passage
- metroUrban rail transit
- tunnelEnclosed underground route
- conduitTube conveying fluid or cables
pipeline · utility · drainage · culvert · aqueduct · cistern · basement · cellar
cavern
Large natural underground chamber
- grottoSmall scenic cavern
- caveUnderground hollow in rock
- stalactiteHanging cave mineral deposit
stalagmite · speleology · spelunker · caving · karst · sinkhole · dripstone · limestone · catacombs · undercroft
concealed
Made invisible deliberately
clandestine · beneath · below · depths · unseen · obscured · underworld · shadowy · cryptic · labyrinthine
excavation
Act of unearthing
stratigraphy · trowel · catacombs · neolithic · ruins · burial · ossuary · necropolis · tumulus · barrow
shaft
Narrow vertical passage
excavation · drill · vein · deposit · quarry · miner · pickaxe · dynamite · blasting · headlamp
sewer
Underground drainage pipe
conduit · pipeline · utility · drainage · culvert · aqueduct · cistern · basement · cellar · foundation
reinforced
Made more resistant
bunker · stockpile · airlock · fortification · nuclear · survivalist · doomsday · war-room · shelter · secure
mole
Subterranean insectivore
- earthwormSegmented soil-dwelling invertebrate
- troglodyteCave-dwelling person
- batFlying mammal or sports club
- Earth/Landearth, land, ground, soil, dirt
- "Sub-" wordssubway, submarine, subtract, subject, suburb
- Burrowersaardvark, aardvarks, badger, badgers, gopher
- dungeondungeon, oubliette, cell bars, torture chamber, chains
- place adjectivescoastal, suburban, urban, rural, northern
- terrain wordshilly, rocky, muddy, sandy, flat
subterraneanaerial
Elevated, or signal-catcher
aboveground · surface · overhead · elevated · airborne
subterraneanovert
Plainly apparent to all
open · exposed · aboveboard · visible · aboveground
- subterranean riverWatercourse beneath the surface
- subterranean worldsRealms existing below ground
territory, terrain, terrestrial, terra, Mediterranean, terrarium, subterrestrial