# underground

/ˈəndɝˌɡɹaʊnd/ (US)

Source: https://englishreference.com/word/underground
Updated: 2026-06-19

## Senses

### 1. below the surface

adjective · CEFR A2

located or happening under the ground.

For teachers: situated, occurring, or operating below the surface of the earth.

- The hotel has an underground car park for its guests.
- The engineers discovered an extensive network of underground streams that complicated the foundation work for the new skyscraper.

### 2. alternative or secret

adjective · CEFR B2

secret or outside of the mainstream, often used for art, music, or politics.

For teachers: relating to a subculture or movement that is unofficial, non-mainstream, or hidden from authorities.

- He plays guitar in an underground rock band that only performs in small clubs.
- The underground press played a crucial role in distributing information during the years of strict government censorship.

### 3. below the ground

adverb · CEFR A2

under the surface of the earth.

For teachers: below the surface of the ground; in or into a subterranean location.

- Rabbits live underground in tunnels called burrows.
- The utility company decided to move all the power lines underground to protect them from severe winter storms.

### 4. into hiding

adverb · CEFR B2

into a place or state of hiding to avoid being caught.

For teachers: into a state of secrecy or concealment, typically to evade observation or arrest.

- The political leader went underground after the police started looking for him.
- After the failed coup, the remaining activists went underground to reorganise their movement without fear of immediate detection.

### 5. train system

noun · CEFR A2 · British English

a railway system that runs under the ground in a city.

For teachers: an electric passenger railway system operating in tunnels beneath a city surface.

- It is much faster to take the underground than to drive through the city centre.
- The London Underground is the oldest subterranean railway network in the world, with some sections dating back to 1863.

Usage: Often used with the definite article 'the'.

Teaching tip: In the UK, people say 'the Underground' or 'the Tube'; in the US, 'the subway' is the standard term.

### 6. resistance movement

noun · CEFR C1 · Formal

a secret group of people working together to fight against a government.

For teachers: a clandestine organisation or movement engaged in resisting an established government or occupying power.

- She joined the underground to help fight for her country's freedom.
- Members of the French underground risked their lives to gather intelligence and sabotage enemy supply lines during the occupation.

Usage: Usually used with the definite article 'the'.

## Examples

- I take the underground to work every morning.
- The city's underground is the fastest way to travel between the museum and the main square during rush hour.
- Urban planners argue that expanding the underground is essential for reducing the carbon footprint of the city's daily commuters.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.