72 entries under adjective topic. ×

2
forbidden
2
impossible(unreasonable, useless, absurd, hopeless)
2
impracticable
2
incomprehensible(solid, dense)
2
invulnerable(strong, resolute, unaffected, unyielding)
2
murky(solid, dense)
2
mysterious(solid, dense)
2
sealed(unaffected, unyielding, unbending, resistant)
2
unattainable(inaccessible, impossible, impossibility)
2
untrodden(closure, closed)
1
blind(hidden, covered)
1
bulletproof(solid, dense, untouchable, invincible)
1
hard(solid, dense)
1
heavy
1
hermetic(solid, dense, unaffected, unyielding)
1
impassive(unaffected, unyielding, unbending, resistant)
1
inextricable
1
inviolable(solid, dense)
1
trackless
0
Delphic(solid, dense)
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APASmart Define. (2015). impassable thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/impassable/thesaurus/synonyms
ChicagoSmart Define. 2015. "impassable thesaurus" https://smartdefine.org/impassable/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, impassable thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/impassable/thesaurus/synonyms>.
MLASmart Define. "impassable thesaurus" 14 April 2015. Web. 23 September 2026. <https://smartdefine.org/impassable/thesaurus/synonyms>