underground

/'ʌndəgraund/
Học thuật
Thân thiện
underground

The train travels quickly through the underground tunnel.

Definition
  1. Adjective:

    • Situated or occurring beneath the surface of the earth: Refers to something located or happening below ground level.
    • Operating or done in secret, especially for political purposes: Refers to activities, organizations, or movements that are hidden, clandestine, or subversive.
  2. Adverb:

    • Beneath the surface of the earth: Describes the location or movement of something below ground.
    • In or into secrecy or hiding: Describes the state or action of operating in a concealed or clandestine manner.
  3. Noun:

    • A subway system: An electric railway that operates in tunnels beneath a city.
    • A secret organization or movement: A group working covertly, often to oppose a government or ruling power.
Usage Examples
  • Adjective:

    • The city has an extensive underground network of pipes and cables.
    • During the war, he was part of the underground resistance movement.
  • Adverb:

    • The roots of the plant spread underground.
    • The political activists were forced to go underground to avoid arrest.
  • Noun:

    • I take the underground to work every day; it's very fast.
    • She was a key member of the anti-fascist underground.
Advanced Usage
  • "to go underground": to go into hiding or to begin operating secretly.
    • After the coup, the opposition leaders had to go underground.
  • "underground press": secret or unofficial newspapers or publications, often critical of the government.
    • The underground press played a vital role in spreading information during the dictatorship.
Variants and Related Words
  • Undergrounder (n): A person who is part of an underground movement or who lives an alternative, non-mainstream lifestyle.
  • Underground (as a cultural adjective): Relating to artistic, musical, or social movements that are avant-garde, experimental, or outside the mainstream.
    • The band started in the underground music scene before achieving mainstream success.
Synonyms
  • Adjective (secret): Clandestine, covert, secret, subversive.
  • Adjective (below ground): Subterranean, belowground.
  • Noun (railway): Subway, metro, tube.
  • Noun (secret group): Resistance, clandestine organization.
Related Phrases
  • Underground economy: Economic activity that is not officially recorded or taxed; black market.
    • A significant portion of the country's transactions occur in the underground economy.
  • Underground art: Art that is experimental and not commercially oriented.
    • The gallery specializes in showcasing underground art.
Idioms
  • To drive something underground: To force an activity or organization to operate in secret.
    • Harsh new laws drove the protest movement underground.
underground

The train travels quickly through the underground tunnel.

Adjective
  1. conducted with or marked by hidden aims or methods
    • clandestine intelligence operations
    • cloak-and-dagger activities behind enemy lines
    • hole-and-corner intrigue
    • secret missions
    • a secret agent
    • secret sales of arms
    • surreptitious mobilization of troops
    • an undercover investigation
    • underground resistance
  2. under the level of the ground
    • belowground storage areas
    • underground caverns
Adverb
  1. beneath the surface of the earth
    • water flowing underground
  2. in or into hiding or secret operation
    • the organization was driven underground
Noun
  1. an electric railway operating below the surface of the ground (usually in a city)
    • in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'
  2. a secret group organized to overthrow a government or occupation force