Un"der*ground` (?), n.
The place or space beneath the surface of the ground; subterranean space.
A spirit raised from depth of underground.
Shak.
© Webster 1913.
Un"der*ground`, a.
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 ∨ railway. See under Railroad.
© Webster 1913.
Un"der*ground`, adv.
Beneath the surface of the earth.
© Webster 1913.