Subterranean

(a.) Situated or occurring below the surface of the earth; as subterranean creatures.

Thesaurus Entries

abstruse, beclouded, blind, close, clouded, concealed, covered, covert, deep-buried, drowned, eclipsed, engulfed, flooded, guarded, hid, hidden, immersed, in a cloud, in a fog, in eclipse, in purdah, in the wings, incommunicado, inundated, latent, mysterious, obfuscated, obscure, obscured, occult, privy, recondite, secluded, secluse, secret, sequestered, shrouded, subaqueous, submarine, submerged, submersed, subterranean, subterraneous, sunken, under an eclipse, under cover, under house arrest, under wraps, underground, undersea, underwater, unknown, wrapped in clouds