Read this dictionary entry for subterranean.

Question

subterranean (sŭb-tә-rā-nē-әn)
adj.
Underground.
Hidden; secret. The subterranean cave hid the bank robber’s loot. (from Latin sub- “under” + terra “earth”)
What is the root of subterranean?

terra

ean

sub

an

Answer 1

The root of "subterranean" is "terra," which means "earth" in Latin.