n. a secret group organized to overthrow a government or occupation force

n. an electric railway operating below the surface of the ground (usually in a city); "in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'"

adv. in or into hiding or secret operation; "the organization was driven underground"

adv. beneath the surface of the earth; "water flowing underground"

adj. under the level of the ground; "belowground storage areas"; "underground caverns"

adj. (used of the military) not belonging to or engaged in by regular army forces; "irregular troops"; "irregular warfare"

adj. conducted with or marked by hidden aims or methods; "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"

n. a commercial organization serving as a common carrier

adj. marked by deception; "achieved success in business only by underhand methods"

adj. marked by quiet and caution and secrecy; taking pains to avoid being observed; "a furtive manner"; "a sneak attack"; "stealthy footsteps"; "a surreptitious glance at his watch"

adj. beneath the surface of the sea

adj. beneath the surface of the water; "submerged rocks"

adj. being or operating under the surface of the earth; "subterranean passages"; "a subsurface flow of water"

adj. favoring one person or side over another; "a biased account of the trial"; "a decision that was partial to the defendant"

adj. based upon or representing political parties: "party politics"; "party leaders"

adj. devoted to a political party

adj. having or marked by a strong tendency especially a controversial one; "a tendentious account of recent elections"; "distinguishing between verifiable fact and tendentious assertion"

adj. acting together in secret toward a fraudulent or illegal end

adj. not accessible to view; "concealed (or hidden) damage"; "in stormy weather the stars are out of sight"

adj. having markings suggestive of a mask; "the masked face of a raccoon"

adj. with your identity concealed

adj. protected from danger or bad weather; "a sheltered harbor"

adj. indulging only covertly; "a secret alcoholic"

adj. lying beyond what is openly revealed or avowed (especially being kept in the background or deliberately concealed); "subterranean motives for murder"; "looked too closely for an ulterior purpose in all knowledge"- Bertrand Russell

adj. not made known

adj. open and observable; not secret or hidden; "an overt lie"; "overt hostility"; "overt intelligence gathering"; "open ballots"