59 entries under underground topic. ×

16
hidden(verb, adjective, obscure, secret, unknown)
7
obscured(verb, adjective, secret, shady, hidden)
5
disguised(noun, verb, adjective, secure, obscure)
4
buried(verb, adjective, secret, unknown, hidden)
3
camouflaged(verb, adjective, secure, obscure, mysterious)
2
deep(obscure, unknown, clandestine, undisclosed)
2
subterranean(adjective, hidden)
2
under wraps(expression, secret, hidden, clandestine)
1
arcane(obscure, unknown, clandestine, undisclosed)
1
clandestine(secret, unknown, hidden, concealed)
1
dissembled(verb, clandestine, undisclosed)
1
hush-hush(secret, hidden, clandestine, undisclosed)
1
on the QT(expression, idiom, obscure, unknown, hidden)
1
out-of-the-way(obscure, unknown, clandestine, undisclosed)
1
private(obscure, secret, unknown, hidden)
1
reticent(obscure, unknown, clandestine, undisclosed)
1
retired(obscure, unknown, clandestine, undisclosed)
1
secretive(clandestine, undisclosed)
1
sunken(adjective, hidden)
1
surreptitious(secret, unknown, hidden, concealed)
<123>
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APASmart Define. (2015). covered thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/covered/thesaurus/synonyms
ChicagoSmart Define. 2015. "covered thesaurus" https://smartdefine.org/covered/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, covered thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/covered/thesaurus/synonyms>.
MLASmart Define. "covered thesaurus" 13 April 2015. Web. 22 September 2026. <https://smartdefine.org/covered/thesaurus/synonyms>