173 entries under persistent topic. ×

49
enduring(adjective, calm, close, strong, sound)
49
stout(adjective, calm, strong, sound, tough)
48
permanent(adjective, calm, strong, secure, tough)
48
unalterable(adjective, characteristic, calm, strong, hard)
47
inexorable(adjective, mean, strong, hard, tough)
47
obdurate(adjective, strong, hard, secure, tough)
45
lasting(adjective, calm, strong, secure, tough)
44
unwavering(adjective, calm, close, strong, secure)
44
invariable(adjective, calm, strong, secure, strain)
41
unshakable(adjective, mean, strong, hard, complete)
40
solid(adjective, calm, good, close, set)
38
perpetual(adjective, strain, determined, familiar, steady)
38
stabile(adjective, calm, strong, secure, strain)
38
sustained(adjective, strain, firmness, continuous)
37
insistent(adjective, set, determined, steady, resolute)
35
relentless(adjective, mean, strong, hard, tough)
34
unrelenting(adjective, mean, strong, hard, tough)
32
adamant(adjective, mean, strong, hard, secure)
31
tough(adjective, calm, mean, clear, strong)
30
staunch(noun, adjective, calm, good, close)
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APASmart Define. (2016). firm thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/firm/thesaurus/synonyms
ChicagoSmart Define. 2016. "firm thesaurus" https://smartdefine.org/firm/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, firm thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/firm/thesaurus/synonyms>.
MLASmart Define. "firm thesaurus" 31 March 2016. Web. 22 September 2026. <https://smartdefine.org/firm/thesaurus/synonyms>