33
enduring(adjective, calm, close, strong, complete)
32
unswerving(adjective, close, strong, tough, correct)
31
lasting(adjective, calm, strong, secure, strain)
31
loyal(adjective, good, close, strong, kind)
31
unfaltering(adjective, complete, firm, total, solid)
28
faithful(adjective, good, close, strong, kind)
27
fixed(adjective, move, calm, strong, complete)
27
immovable(adjective, move, secure, firm, solid)
27
inflexible(adjective, strong, secure, tough, flat)
26
invariable(adjective, calm, strong, secure, strain)
26
obdurate(adjective, strong, secure, tough, flat)
26
unflinching(adjective, strong, flat, firm, certain)
25
durable(adjective, calm, strong, secure, strain)
25
settled(adjective, strong, secure, easy, strain)
24
unalterable(adjective, calm, strong, secure, strain)
23
tenacious(adjective, clear, strong, secure, tough)
23
uncompromising(adjective, clear, secure, tough, severe)
22
dogged(adjective, strong, tough, firm, solid)
22
long-standing(adjective, strain, firmness, labour, hardiness)
22
persevering(adjective, strong, tough, flat, firm)
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APASmart Define. (2016). steadfast thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/steadfast/thesaurus/synonyms
ChicagoSmart Define. 2016. "steadfast thesaurus" https://smartdefine.org/steadfast/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, steadfast thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/steadfast/thesaurus/synonyms>.
MLASmart Define. "steadfast thesaurus" 11 March 2016. Web. 21 September 2026. <https://smartdefine.org/steadfast/thesaurus/synonyms>