Underground | Mean of underground in English Dictionary

/ˈʌndɚˌgraʊnd/

• located or occurring below the surface of the earth
1. underground parking garages
2. an underground explosion
• secret and usually illegal
1. an underground deal
2. The drugs are supplied through an underground network.
• of, relating to, or produced in a social and artistic world that is different and separate from the main part of society
1. She loves the city's underground music scene.
2. underground newspapers/movies

• below the surface of the earth
1. The wires run underground.
2. animals that live underground
• in or into a place that is hidden or secret
1. They had been living underground as fugitives.
2. The political party went underground [=started working in secret] after the new government took power.
• Noun
• a system of trains that run below the ground in a large city
1. I've ridden on the New York subway, the Paris Metro, and the London Underground.
2. She commutes by underground.
• a group of people who secretly work to oppose or overthrow a government