Synonyms|289Antonyms|101|Broader|6Narrower|0Related|320

23 entries under firmness topic. ×

18
permanent(adjective, strain, labour, hardiness)
18
steady(adjective, strain, safe, labour)
18
viable(adjective, strain, labour, hardiness)
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APASmart Define. (2015). impregnable thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/impregnable/thesaurus/synonyms
ChicagoSmart Define. 2015. "impregnable thesaurus" https://smartdefine.org/impregnable/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, impregnable thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/impregnable/thesaurus/synonyms>.
MLASmart Define. "impregnable thesaurus" 10 April 2015. Web. 23 September 2026. <https://smartdefine.org/impregnable/thesaurus/synonyms>