69 entries under underground topic. ×

9
furtive(adjective, obscure, unknown, sneaky)
7
secret(adjective, hidden, clandestine, undisclosed)
4
surreptitious(adjective, clandestine, sneaky, covert)
3
clandestine(adjective, undisclosed, sneaky, covert)
3
covert(adjective, clandestine, undisclosed, sneaky)
3
private(adjective, obscure, unknown, clandestine)
3
secretive(adjective, clandestine, undisclosed, sneaky)
3
underhand(adjective, clandestine, undisclosed, sneaky)
2
esoteric(adjective, obscure, unknown, clandestine)
2
stealthy(adjective, clandestine, sneaky, covert)
1
backdoor(adjective, obscure, unknown, clandestine)
1
camouflaged(adjective, obscure, unknown, clandestine)
1
cloak-and-dagger(adjective, obscure, unknown, clandestine)
1
close(adjective, obscure, unknown, clandestine)
1
clouded(adjective, obscure, unknown, clandestine)
1
covered(adjective, obscure, unknown, clandestine)
1
disguised(adjective, obscure, unknown, clandestine)
1
enigmatical(adjective, obscure, unknown, clandestine)
1
hidden(adjective, clandestine, undisclosed, sneaky)
1
hush-hush(adjective, clandestine, undisclosed, sneaky)
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APASmart Define. (2015). conspiratorial thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/conspiratorial/thesaurus/synonyms
ChicagoSmart Define. 2015. "conspiratorial thesaurus" https://smartdefine.org/conspiratorial/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2015, conspiratorial thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/conspiratorial/thesaurus/synonyms>.
MLASmart Define. "conspiratorial thesaurus" 13 April 2015. Web. 24 September 2026. <https://smartdefine.org/conspiratorial/thesaurus/synonyms>