underground

Located below the surface of the earth.

• The house has an underground garage.
• Workers repaired the underground pipes.
• Many animals live in underground tunnels.

Similar words: subterranean

Opposites: aboveground

Common phrases: underground tunnel, underground water, underground station

Kept secret or known only to a small group of people.

• They joined an underground resistance group.
• The police discovered an underground network.
• Their underground meetings took place in a cellar.

Similar words: secret, clandestine, covert

Opposites: open

Common phrases: underground movement, underground network, underground activity

Belonging to art or culture outside what most people know or accept.

• She enjoys underground music.
• The club became a centre for underground artists.
• His underground films rarely appeared in large cinemas.

Similar words: alternative, nonmainstream

Opposites: mainstream

Common phrases: underground music, underground scene, underground film

Under the surface of the earth.

• The train travels underground here.
• They buried the cable underground.
• How far underground do the roots grow?

Similar words: below ground

Opposites: aboveground

Common phrases: go underground, buried underground, deep underground

A city train system that runs mostly below the streets.

• We took the underground to the museum.
• The nearest underground station is five minutes away.
• Does the underground run all night?

Similar words: metro, subway, tube

Common phrases: the underground, underground station, take the underground

A secret group or movement that opposes the authorities or accepted political ideas.

• She joined the underground during the war.
• The underground printed leaflets against the government.
• Members of the underground carried messages across the border.

Similar words: resistance

Common phrases: join the underground, the political underground, underground members