underground
gb/ˈʌndɚɡɹˌaʊnd/ us/ˈʌndɚɡɹˌaʊnd/
A2
English
~ 4300
Senses
0 senses
Noun
A2
entity
1
a subway train network
A system of trains that run in tunnels under a city.
Usage pattern:
to take the underground to [a place]
Common mistake:
Learners may confuse 'underground' (UK English) with 'subway' (US English), which in US can also mean an underground walkway or passage.
Synonyms
subway (Commonly used in American English for the same concept.)
|
metro (Used in many countries, especially in Europe, for an underground train system.)
Antonyms
overground train (A train that runs on tracks above the surface.)
Collocations
take the underground
|underground station
|underground network
|underground map
Themes
transportation
|city life
|travel
Examples
- The underground is the fastest way to get across London.
- She takes the underground to work every morning.
- The city has expanded its underground to reach the suburbs.
- Tourists often find the underground confusing at first.
Learner examples
- I go to school by underground.
- The underground is very busy in the morning.
- We took the underground to the museum.
- He works near an underground station.
adjective
B1
property
2
below the earth's surface
Located or happening under the ground.
Synonyms
subterranean (A more formal or technical word for 'underground'.)
Antonyms
aboveground (Situated or occurring on or above the earth's surface.)
Collocations
underground tunnel
|underground parking
|underground cable
Themes
geography
|construction
|space
|nature
Examples
- They built an underground garage for the apartment complex.
- The underground pipes need repair.
- The miners work in underground shafts.
Learner examples
- We walked through an underground tunnel.
- There is an underground car park here.
- The shop has an underground storeroom.
Noun
B2
entity
3
secret resistance group
A secret group that works against people in power.
Synonyms
resistance (Often used for organized opposition during wartime or occupation.)
|
clandestine group (Emphasizes secrecy and hidden operations.)
Antonyms
official organization (An open, legally recognized group operating under public authority.)
Collocations
join the underground
|underground movement
|underground network
Themes
politics
|history
|law
Examples
- During the war, he joined the underground to fight the occupation.
- The underground distributed banned newspapers.
- Many members of the underground were arrested by the regime.
Learner examples
- She was part of an underground group.
- The underground helped people escape.
- They hid with help from the underground.
adjective
B2
property
4
secret and hidden from public view
Secret and not known by many people, sometimes illegal.
Synonyms
covert (Focuses on being deliberately concealed.)
|
hidden (General term for not visible or known.)
Antonyms
mainstream (Openly accepted by the majority of society.)
Collocations
underground club
|underground art scene
|underground economy
Themes
culture
|law
|core_vocabulary
Examples
- They attended an underground music festival in a warehouse.
- The film became popular through underground screenings.
- There's an underground market for rare books.
Learner examples
- He likes underground music.
- They went to an underground party.
- The shop sells underground comics.
Grammar
Dictionary form
underground
IPA
GB/ˈʌndɚɡɹˌaʊnd/
US/ˈʌndɚɡɹˌaʊnd/
Syllables & stress
un - der - ground (3 syllables)
Stress on 1st syllable (un)
Word forms
Adjective
- Base: underground
Noun
- Base: underground
- Plural: underground, undergrounds
Word family
Forms
undergrounds
noun
Core family
ground
noun A1
Negative and opposite forms
aboveground
adjective
Expressions
go underground
1/ɡˈoʊ ˈʌndɚɡɹˌaʊnd/
idiom
hide to avoid detection
To hide or work secretly so people cannot find you.
Examples
- After the scandal, he went underground to avoid reporters.
- The group went underground after being declared illegal.
underground economy
1/ˈʌndɚɡɹˌaʊnd ɪkˈɑnəmi/
fixed phrase
hidden or illegal economic activity
Business activities that are not reported to the government and are often illegal.
Examples
- The government is trying to crack down on the underground economy.
- Many workers in the underground economy are paid in cash.
underground movement
1/ˈʌndɚɡɹˌaʊnd mˈuvmənt/
fixed phrase
secret opposition group or trend
A secret group that works against those in power or against normal ways of doing things.
Examples
- The novel was inspired by an underground movement in the 1970s.
- An underground movement is gaining support among young people.