1
solitary(close, quiet, private, isolated, secluded)
1
soundproof
1
staunch
1
stifled
1
stopped(adjective, closed)
1
stormproof
1
stormtight
1
suppressed
1
thick
1
tightly sealed(adjective, tight, proof, impervious)
1
top-secret
1
top secret
1
totally enclosed(adjective, tight, proof, impervious)
1
tucked away(expression, close, quiet, private, isolated)
1
ulterior
1
unapproachable(close, quiet, private, unaffected, unyielding)
1
unbreatheable
1
under security
1
under wraps
1
undetected(obscure, dark, secret, unknown, hidden)
11 years ago|4.8k views|share |citing 
APASmart Define. (2015). hermetic thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/hermetic/thesaurus/synonyms
ChicagoSmart Define. 2015. "hermetic thesaurus" https://smartdefine.org/hermetic/thesaurus/synonyms (accessed September 26, 2026).
HarvardSmart Define 2015, hermetic thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/hermetic/thesaurus/synonyms>.
MLASmart Define. "hermetic thesaurus" 10 April 2015. Web. 26 September 2026. <https://smartdefine.org/hermetic/thesaurus/synonyms>