100 entries under hard topic. ×

4
strong(adjective, set, sound, tough)
4
tough(adjective, strong, sound, continue)
3
hardy(adjective, set, strong, sound)
3
rugged(adjective, set, strong, sound)
3
stalwart(adjective, strong, sound, tough)
2
dense(adjective, set, strong, tough)
2
flinty(adjective, strong, firm, solid)
2
hard-bitten(adjective, strong, continue, solid)
2
lusty(adjective, strong, solid, stiff)
2
mighty(adjective, strong, sound, tough)
2
obdurate(adjective, strong, tough, firm)
2
resistant(adjective, strong, solid, stiff)
2
robust(adjective, strong, sound, tough)
2
rocky(adjective, set, strong, compact)
2
solid(adjective, set, strong, sound)
2
steely(adjective, strong, tough, stiff)
2
stony(adjective, set, strong, indifferent)
2
stout(adjective, strong, sound, tough)
2
strapping(adjective, strong, sound, tough)
2
sturdy(adjective, strong, sound, tough)
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APASmart Define. (2015). hard as nails thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/hard_as_nails/thesaurus/synonyms
ChicagoSmart Define. 2015. "hard as nails thesaurus" https://smartdefine.org/hard_as_nails/thesaurus/synonyms (accessed September 27, 2026).
HarvardSmart Define 2015, hard as nails thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/hard_as_nails/thesaurus/synonyms>.
MLASmart Define. "hard as nails thesaurus" 10 April 2015. Web. 27 September 2026. <https://smartdefine.org/hard_as_nails/thesaurus/synonyms>