1
hermetically-impervious(adjective, tight, proof, impervious)
1
hermetically-sealed(adjective, tight, proof, impervious)
1
holeproof
1
hush-hush
1
imperceivable(obscure, dark, secret, unknown, hidden)
1
impervious to
1
in the dark(expression, idiom, obscure, dark, unknown)
1
incomprehensible
1
indiscernible(obscure, solid, dark, unknown, dense)
1
insular(close, quiet, private, isolated, secluded)
1
invisible(obscure, dark, deep, mysterious, unknown)
1
isolate(close, quiet, private, isolated, secluded)
1
isolated(adjective, quiet, private)
1
latched(adjective, closed)
1
leakproof
1
leaktight(adjective, tight, proof, impervious)
1
lightproof
1
lighttight
1
liquid-tight(adjective, tight, proof, impervious)
1
locked(adjective, closed)
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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>