underground lake; subterranean lake
underground train; subway
burying; underground installation (cables, etc.)
underground space; subterranean space; subterranea
underground shopping center; underground shopping centre
second basement level; subbasement
to go underground; to go into hiding
semibasement; semi-basement
basement of a department store (where foodstuffs are usually sold)
subway; tube; underground railroad; underground railway
member of a non-famous boy band or girl group; (lit.) underground idol
underground organization; underground organisation
basement floor; underground floor
underground activity; underground activities; underground movement
underground shopping arcade connected to a station
underground publication; underground publishing; samizdat
clandestine bank; underground bank
underground economy; black economy
underground wire or cable
underground train station
underground activities; secret maneuvering
London Underground mosquito (Culex pipiens f. molestus)
sunken hearth; sunken fireplace