Underground - Definition

adv 1: in or into hiding or secret operation; "the organization
was driven underground"
2: beneath the surface of the earth; "water flowing underground"
adj 1: under the level of the ground; "belowground storage
areas"; "underground caverns" [syn: belowground,
underground]
2: 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" [syn: clandestine,
cloak-and-dagger, hole-and-corner(a), hugger-mugger,
hush-hush, secret, surreptitious, undercover,
underground]
n 1: a secret group organized to overthrow a government or
occupation force [syn: underground, resistance]
2: 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'" [syn: metro, tube, underground, subway
system, subway]