46 entries under underground topic. ×

26
underhand(adjective, mean, smooth, smart, dishonest)
9
sneak(adjective, close, clandestine, undisclosed)
7
underhanded(adjective, dishonest, cunning, deceitful, unpredictable)
6
conspiratorial(adjective, obscure, unknown, sneaky)
3
arcane(adjective, obscure, strange, secret, unknown)
3
confidential(adjective, secret, hidden, spy, clandestine)
3
mystical(obscure, strange, unknown, clandestine)
3
occult(obscure, strange, unknown, clandestine)
3
unknown(obscure, strange, clandestine, curious)
2
abstruse(obscure, strange, unknown, clandestine)
2
backdoor(close, obscure, unknown, clandestine)
2
classified(adjective, obscure, secret, unknown, clandestine)
2
esoteric(obscure, strange, unknown, clandestine)
2
in ambush(expression, close, clandestine, undisclosed)
2
recondite(adjective, obscure, strange, unknown, clandestine)
2
restricted(adjective, secret, clandestine, undisclosed)
1
cloak-and-dagger(obscure, unknown, hidden, clandestine)
1
closet(adjective, obscure, unknown, hidden, clandestine)
1
discreet(close, clandestine, undisclosed)
1
dissembled(close, secret, hidden, clandestine)
<123>
11 years ago|15k views|share |citing 
APASmart Define. (2015). furtive thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/furtive/thesaurus/synonyms
ChicagoSmart Define. 2015. "furtive thesaurus" https://smartdefine.org/furtive/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2015, furtive thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/furtive/thesaurus/synonyms>.
MLASmart Define. "furtive thesaurus" 13 April 2015. Web. 28 September 2026. <https://smartdefine.org/furtive/thesaurus/synonyms>