1
sneaky(clandestine, underground, undisclosed)
1
stabilized(verb, ordered)
1
stealth
1
stifled
1
structured(verb, ordered)
1
sub-rosa(sensitive, secret, clandestine, underground, undisclosed)
1
subordinated(verb, ordered)
1
supported(verb, ordered)
1
suppressed
1
synchronized
1
tabular
1
tabulated
1
tight-lipped
1
ulterior
1
unacknowledged(sensitive, clandestine, underground, undisclosed, sub-rosa)
1
unbreatheable
1
under-the-table(sensitive, secret, clandestine, underground, undisclosed)
1
under false pretense(expression, idiom, sensitive, clandestine, underground)
1
under security
1
underground(obscure, unknown, clandestine, undisclosed, unrevealed)
11 years ago|7.8k views|share |citing 
APASmart Define. (2015). classified thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/classified/thesaurus/synonyms
ChicagoSmart Define. 2015. "classified thesaurus" https://smartdefine.org/classified/thesaurus/synonyms (accessed September 26, 2026).
HarvardSmart Define 2015, classified thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/classified/thesaurus/synonyms>.
MLASmart Define. "classified thesaurus" 14 April 2015. Web. 26 September 2026. <https://smartdefine.org/classified/thesaurus/synonyms>