underground

adj 1: under the level of the ground; "belowground storage areas";

"underground caverns" [syn: {belowground}]

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}, {on the quiet(p)}, {secret},

{surreptitious}, {undercover}]

3: used of independent armed resistance forces; "guerrilla

warfare"; "partisan forces" [syn: {guerrilla(a)}, {guerilla(a)},

{irregular}]

n 1: a secret group organized to overthrow a government or

occupation force [syn: {resistance}]

2: an electric underground railway [syn: {metro}, {subway}, {tube}]

adv 1: in or into hiding or secret operation; "the organization was

driven underground"

2: beneath the surface of the earth; "water flowing

underground"