3
flawless
3
gastight(adjective, tight, proof, impervious, hermetic)
3
invulnerable(adjective, certain)
3
pressure-tight(adjective, tight, proof, impervious, hermetic)
3
proof(adjective, tight, impervious, hermetic)
3
secure(verb, adjective, closed)
3
shut(verb, adjective, closed, sealed)
2
close
2
enclosed(adjective, tight, proof, impervious, hermetic)
2
firm
2
hermetically sealed
2
indisputable(adjective, certain)
2
pressurized(adjective, tight, proof, impervious, hermetic)
2
rainproof(adjective, resistant, impervious, watertight, waterproof)
2
tightly sealed(expression, adjective, idiom, tight, proof)
1
air-locked(adjective, tight, proof, impervious, hermetic)
1
air-proof(adjective, tight, proof, impervious, hermetic)
1
air tight(expression, idiom)
1
ballproof
1
blind(adjective, sound, firm, fast, short)
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APASmart Define. (2015). airtight thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/airtight/thesaurus/synonyms
ChicagoSmart Define. 2015. "airtight thesaurus" https://smartdefine.org/airtight/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2015, airtight thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/airtight/thesaurus/synonyms>.
MLASmart Define. "airtight thesaurus" 14 April 2015. Web. 25 September 2026. <https://smartdefine.org/airtight/thesaurus/synonyms>