11
sneak(adjective, clandestine, underground, undisclosed)
9
sneaking(adjective, mean, smooth, honest, dishonest)
8
oblique(adjective, obscure, dishonest, cunning, deceitful)
8
underhanded(adjective, dishonest, cunning, deceitful, crafty)
7
backstairs(adjective, clandestine, underground, undisclosed)
7
cloak-and-dagger(adjective, full, secret, clandestine, underground)
7
devious(adjective, dishonest, cunning, deceitful, tricky)
7
fraudulent(adjective, deception, dishonest, cunning, deceitful)
6
confidential(adjective, secret, hidden, spy, clandestine)
6
deceitful(adjective, mean, smooth, dishonest, crafty)
6
occult(noun, secret, unknown, hidden, underground)
6
privy
5
crafty(adjective, mean, smooth, dishonest, cunning)
5
factitious(adjective, deception, untruth)
5
lurking
5
quiet(adjective, intriguing)
5
under-the-table(adjective, secret, hidden, clandestine, sneaky)
5
undisclosed(adjective, secret, unknown, hidden, concealed)
5
veiled(adjective, secret, unknown, hidden, clandestine)
4
ambiguous(obscure, clandestine, underground, undisclosed)
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APASmart Define. (2015). surreptitious thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/surreptitious/thesaurus/synonyms
ChicagoSmart Define. 2015. "surreptitious thesaurus" https://smartdefine.org/surreptitious/thesaurus/synonyms (accessed September 26, 2026).
HarvardSmart Define 2015, surreptitious thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/surreptitious/thesaurus/synonyms>.
MLASmart Define. "surreptitious thesaurus" 13 April 2015. Web. 26 September 2026. <https://smartdefine.org/surreptitious/thesaurus/synonyms>