1
temper(noun, protection, security, rigidity, hardness)
1
tensile strength(noun, expression, protection, security, rigidity)
1
tightness(noun, mass, bulk, density, thickness)
1
unintelligibility
1
vagueness
1
viscosity
0
air of mystery(expression, idiom)
0
airtightness(noun, protection, security, impermeability, waterproofness)
0
ambitiousness
0
arcaneness
0
bulk(noun, mass, density, thickness, impermeability)
0
cold-bloodedness(noun, cruelty)
0
cold-heartedness
0
concentration(noun, mass, thickness)
0
concreteness(noun, mass, thickness)
0
crowding
0
darkness
0
denser
0
grandiosity
0
hardheartedness(noun, cruelty)
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APASmart Define. (2015). impenetrability thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/impenetrability/thesaurus/synonyms
ChicagoSmart Define. 2015. "impenetrability thesaurus" https://smartdefine.org/impenetrability/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, impenetrability thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/impenetrability/thesaurus/synonyms>.
MLASmart Define. "impenetrability thesaurus" 14 April 2015. Web. 23 September 2026. <https://smartdefine.org/impenetrability/thesaurus/synonyms>