5
covered(adjective, obscure, unknown, hidden, concealed)
5
detailed(adjective, intimate, private, personal, innermost)
5
discreet(adjective, personal, clandestine, underground, undisclosed)
5
exclusive(adjective, individual, private, personal, confidential)
5
exhaustive(adjective, intimate, private, personal, innermost)
5
inscrutable(adjective, dark, strange, uncertain, blank)
5
insidious(adjective, mean, smooth, dishonest, cunning)
5
obscured(adjective, separate, hidden, concealed, underhanded)
5
penetrating(adjective, heavy, deep, thoughtful, serious)
5
privileged(adjective, sensitive, private, confidential, classified)
5
retired(verb, adjective, close, quiet, obscure)
5
sneak(adjective, clandestine, underground, undisclosed, underhand)
5
thorough(adjective, deep, thoughtful, intimate, private)
5
trick(noun, expertise)
5
ulterior(adjective, separate, unknown, hidden, concealed)
5
unacknowledged(adjective, sensitive, unknown, clandestine, undisclosed)
5
unavowed
5
whodunit(noun, question, puzzle, perplexity, obscurity)
4
code(noun, confidence, mystery, unrevealed, enigma)
4
backstairs(adjective, sensitive, clandestine, underground, undisclosed)
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APASmart Define. (2016). secret thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/secret/thesaurus/synonyms
ChicagoSmart Define. 2016. "secret thesaurus" https://smartdefine.org/secret/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2016, secret thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/secret/thesaurus/synonyms>.
MLASmart Define. "secret thesaurus" 31 March 2016. Web. 25 September 2026. <https://smartdefine.org/secret/thesaurus/synonyms>