67 entries under underground topic. ×

1
masked(secret, hidden, clandestine, sneaky)
1
mysterious(clandestine, undisclosed)
1
top secret(expression, clandestine, undisclosed)
1
unacknowledged(clandestine, undisclosed)
1
under false pretense(expression, idiom, clandestine, undisclosed)
1
veiled(secret, hidden, clandestine, undisclosed)
0
QT(secret, hidden, clandestine, privy)
0
abstruse(clandestine, undisclosed)
0
ambiguous(false, misleading, clandestine, illusory)
0
arcane(clandestine, undisclosed)
0
buried(secret, hidden, clandestine, privy)
0
cloak-and-dagger(clandestine, undisclosed)
0
close(clandestine, undisclosed)
0
closet(clandestine, undisclosed)
0
clouded(clandestine, undisclosed)
0
conspiratorial(clandestine, undisclosed, sneaky, covert)
0
covered(clandestine, undisclosed)
0
cryptic(clandestine, undisclosed)
0
deep(cunning, sly, crafty, clandestine)
0
enigmatical(clandestine, undisclosed)
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APASmart Define. (2016). underhanded thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/underhanded/thesaurus/synonyms
ChicagoSmart Define. 2016. "underhanded thesaurus" https://smartdefine.org/underhanded/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2016, underhanded thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/underhanded/thesaurus/synonyms>.
MLASmart Define. "underhanded thesaurus" 22 January 2016. Web. 24 September 2026. <https://smartdefine.org/underhanded/thesaurus/synonyms>