292 entries under adjective topic. ×

4
unsympathetic(bad, cold, indifferent, detached)
3
apathetic(indifferent, detached, distant, unfeeling)
3
closed
3
closed to(expression, unyielding, unbending, unable)
3
cold(calm, indifferent, restrained, detached)
3
emotionless(bad, cold, aloof, no feelings)
3
hard-boiled(noun, calm, bad, cold)
3
hard-hearted(calm, bad, cold, restrained)
3
impregnable(secure, safe, snug, intact)
3
inflexible(hard, tough, solid, rigid)
3
leakproof
3
steely
3
thick(hard, solid, rigid, dense)
3
tough(noun, set, strong, hard)
3
unconcerned(calm, indifferent, restrained, detached)
3
unpierceable(unyielding, unbending, unable, unreceptive)
2
aloof(calm, indifferent, restrained, detached)
2
close(set, hard, tough, solid)
2
dense(set, hard, tough, solid)
2
durable(sturdy, enduring)
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APASmart Define. (2015). impervious thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/impervious/thesaurus/synonyms
ChicagoSmart Define. 2015. "impervious thesaurus" https://smartdefine.org/impervious/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2015, impervious thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/impervious/thesaurus/synonyms>.
MLASmart Define. "impervious thesaurus" 14 April 2015. Web. 25 September 2026. <https://smartdefine.org/impervious/thesaurus/synonyms>