72 entries under dedicated topic. ×

70
firm(noun, adjective, adverb, calm, close)
64
persistent(adjective, strong, tough, strain, firm)
57
stable(adjective, adverb, strong, secure, tough)
40
steadfast(adjective, characteristic, calm, close, strong)
28
enduring(adjective, state, calm, close, strong)
26
fixed(adjective, adverb, strong, complete, secure)
26
constant(adjective, calm, close, strong, sound)
26
steady(adjective, adverb, calm, close, strong)
22
rigid(adjective, complete, secure, strain, firm)
20
unyielding(adjective, strong, secure, tough, strain)
14
loyal(adjective, characteristic, close, correct, continue)
12
faithful(adjective, characteristic, close, correct, continue)
11
immovable(adjective, strong, secure, firm, solid)
11
staunch(adjective, calm, close, strong, secure)
10
sure(adjective, calm, close, strong, secure)
8
true(adjective, close, strong, tough, correct)
8
unwavering(adjective, calm, close, strong, secure)
7
devoted(adjective, close, correct, warm, firm)
7
immobile(adjective, strong, secure, solid, intense)
7
stubborn(adjective, characteristic, quality, strong, secure)
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APASmart Define. (2016). fast thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/fast/thesaurus/synonyms
ChicagoSmart Define. 2016. "fast thesaurus" https://smartdefine.org/fast/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, fast thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/fast/thesaurus/synonyms>.
MLASmart Define. "fast thesaurus" 1 April 2016. Web. 21 September 2026. <https://smartdefine.org/fast/thesaurus/synonyms>