Synonyms & related words for underground

Find synonyms, related words, and the definition of underground — including subterranean, subway, metro, clandestine, undercover, secret. Dendril is a free visual thesaurus that shows them on an interactive map where stronger matches sit closer to the center — no signup, no ads.

Words related to underground

Explore words related to underground — words associated with it, words that go with it, and its nearest matches in meaning. Related words include hypogeal, hypogeous, subterrane, hypogeum, aboveground, souterrain, tunnels, subsurface. Click any word to make it the center of the map and keep exploring the web of connections.

Synonyms for underground

Common synonyms for underground include subterranean, subway, metro, clandestine, undercover, secret, tube, resistance — words that share a close meaning. Hover or tap any word on the map for its definition and part of speech.

Where does underground come from?

The word underground breaks down into one root of Old English origin: the root under-, from Old English under (“beneath, below”). Explore each root to see other English words built from the same source.