0
secretly
0
secrets
0
sensitive
0
shady
0
stealth
0
strange(obscure, deep, unknown, clandestine, underground)
0
subterranean
0
thieving
0
threshold
0
top-secret(clandestine, underground, undisclosed)
0
trapdoor
0
ulterior
0
under-the-counter
0
under cover(expression, deep, unpublished)
0
under the table(expression, idiom, close, sensitive, inside)
0
under wraps(expression, sensitive, clandestine, underground, undisclosed)
0
underhand(clandestine, underground, undisclosed)
0
undisclosed(obscure, unknown, clandestine, underground, unrevealed)
0
unexposed
0
unintelligible(obscure, deep, unknown, clandestine, underground)
13 years ago|1k views|share |citing 
APASmart Define. (2013). backdoor thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/backdoor/thesaurus/synonyms
ChicagoSmart Define. 2013. "backdoor thesaurus" https://smartdefine.org/backdoor/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2013, backdoor thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/backdoor/thesaurus/synonyms>.
MLASmart Define. "backdoor thesaurus" 19 May 2013. Web. 23 September 2026. <https://smartdefine.org/backdoor/thesaurus/synonyms>