An Encylopedia Britannica Company

underground

1 underground /ˈʌndɚˌgraʊnd/ adjective
1 underground
/ˈʌndɚˌgraʊnd/
adjective
Britannica Dictionary definition of UNDERGROUND
: located or occurring below the surface of the earth
compare aboveground, inground
always used before a noun : secret and usually illegal
always used before a noun : of, relating to, or produced in a social and artistic world that is different and separate from the main part of society
2 underground /ˌʌndɚˈgraʊnd/ adverb
2 underground
/ˌʌndɚˈgraʊnd/
adverb
Britannica Dictionary definition of UNDERGROUND
: below the surface of the earth
: in or into a place that is hidden or secret : out of the view of the public
3 underground /ˈʌndɚˌgraʊnd/ noun
3 underground
/ˈʌndɚˌgraʊnd/
noun
Britannica Dictionary definition of UNDERGROUND
British : a system of trains that run below the ground in a large city : subway
[singular]
[noncount]
the underground : a group of people who secretly work to oppose or overthrow a government