1. The place or space beneath the surface of the ground; subterranean space.
A spirit raised from depth of underground. --Shak.
1. Being below the surface of the ground; as, an underground story or apartment.
2. Done or occurring out of sight; secret. [Colloq.]
Underground railroad or Underground railway. See under Railroad.
Un·der·ground, adv. Beneath the surface of the earth.
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,
3: used of independent armed resistance forces; "guerrilla
warfare"; "partisan forces" [syn: guerrilla(a), guerilla(a),
n 1: a secret group organized to overthrow a government or
occupation force [syn: resistance]
2: electric underground railway [syn: metro, subway, tube]
adv 1: in or into hiding or secret operation; "the organization was
2: beneath the surface of the earth; "water flowing