noun, noun which may take the genitive case particle 'no'
underground; below the ground
Physical space beneath the surface; often used for subways, basements, and subterranean facilities. Antonym: 地上 (above ground).
Antonyms: 地上
地下鉄は地下を走る。
The subway runs underground.
このビルには地下駐車場がある。
This building has an underground parking lot.
noun
the grave; world of the dead
Metaphorical use referring to the realm of the dead; often in literary or fixed expressions.
彼は地下に眠る多くの戦没者を思った。
He thought of the many war dead sleeping beneath the ground.
noun which may take the genitive case particle 'no', noun
underground (activities); secret; illegal
Describes covert, clandestine, or illegal operations, movements, or organizations.
彼らは地下組織を作って抵抗した。
They formed an underground organization and resisted.
地下出版で情報を広めた。
They spread information through underground publishing.