Meaning of the word subterranean in English

What does subterranean mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

subterranean

US /ˌsʌb.təˈreɪ.ni.ən/
UK /ˌsʌb.tərˈeɪ.ni.ən/
"subterranean" picture

Adjective

1.

existing, occurring, or done under the earth's surface

Example:
The city has a vast subterranean network of tunnels.
Scientists are studying subterranean rivers in the cave system.
2.

secret or concealed

Example:
The group operated as a subterranean movement against the regime.
There was a subterranean current of discontent among the workers.