53 entries under underground topic. ×

25
furtive(adjective, mean, smooth, smart, dishonest)
21
sneaky(adjective, mean, bad, smooth, wrong)
13
underhanded(adjective, honest, false, dishonest, cunning)
4
backstairs(adjective, clandestine, undisclosed)
3
conspiratorial(adjective, clandestine, undisclosed, sneaky)
3
deep(sharp, smart, intelligent, cunning, clever)
2
closet(noun, adjective, hidden, clandestine)
2
incognito(secret, hidden, spy, clandestine)
2
undisclosed(adjective, clandestine)
1
camouflaged(secret, hidden, clandestine, undisclosed)
1
cloak-and-dagger(hidden, clandestine, fraudulent, undisclosed)
1
cloaked(secret, hidden, clandestine, sneaky)
1
confidential(secret, hidden, spy, clandestine)
1
disguised(secret, hidden, clandestine, sneaky)
1
dissembled(secret, hidden, clandestine, undisclosed)
1
masked(secret, hidden, clandestine, sneaky)
1
obscure(ambiguous, rambling, clandestine, incidental)
1
out-of-the-way(ambiguous, rambling, clandestine, incidental)
1
sneak(clandestine, undisclosed)
1
unrevealed(adjective, clandestine, undisclosed)
<123>
11 years ago|11k views|share |citing 
APASmart Define. (2015). underhand thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/underhand/thesaurus/synonyms
ChicagoSmart Define. 2015. "underhand thesaurus" https://smartdefine.org/underhand/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, underhand thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/underhand/thesaurus/synonyms>.
MLASmart Define. "underhand thesaurus" 13 April 2015. Web. 23 September 2026. <https://smartdefine.org/underhand/thesaurus/synonyms>