subterraneously
/ˌsʌbtəˈreɪniəsli/
adverb
- In a way that is under the ground.
- Moles live subterraneously, digging tunnels to find food.
- The pipes run subterraneously beneath the city streets.
- The bunker was built subterraneously to protect against bombs.
- In a hidden or secret manner, as if operating underground.
- The organization worked subterraneously to avoid government surveillance.
- The hacker group operated subterraneously for years before being discovered.
- Rumors spread subterraneously through the office before anyone knew the truth.