noun
a secret group organized to overthrow a government or occupation force
Synonyms
noun
an electric railway operating below the surface of the ground (usually in a city)
Synonyms
Examples
- in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'
adjective
under the level of the ground
Synonyms
Examples
- belowground storage areas
- underground caverns
adjective
conducted with or marked by hidden aims or methods
Synonyms
Examples
- 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
adverb
in or into hiding or secret operation
Examples
- the organization was driven underground
adverb
beneath the surface of the earth
Examples
- water flowing underground
adjective
under the level of the ground
Synonyms
Examples
- belowground storage areas
- underground caverns
adjective
conducted with or marked by hidden aims or methods
Synonyms
Examples
- 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
adjective
under the level of the ground
Synonyms
Examples
- belowground storage areas
- underground caverns
adjective
conducted with or marked by hidden aims or methods
Synonyms
Examples
- 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