0
firm(adjective, serious, resolute, persistent, unwavering)
0
fitted out(adjective, unsubmissive)
0
gritty
0
hard(adjective, unfeeling, unsympathetic, hardened, callous)
0
hard-edged(adjective, toughened, cynical, hard-boiled, hard-bitten)
0
hard-nosed(adjective, hard, unfeeling, unsympathetic, hardened)
0
hard as nails(expression, adjective, idiom, determined, serious)
0
heroic
0
impassive(adjective, hard, unfeeling, unsympathetic, hardened)
0
impenitent(adjective, hard, unfeeling, unsympathetic, hardened)
0
indifferent(adjective, hard, unfeeling, unsympathetic, hardened)
0
indomitable
0
inexcitable(adjective, callous, unexcitable)
0
inflexible(adjective, hard, unfeeling, unsympathetic, hardened)
0
insensate(adjective, hard, unfeeling, unsympathetic, hardened)
0
insensible(adjective, hard, unfeeling, unsympathetic, hardened)
0
insensitive(adjective, hard, tough, unfeeling, unsympathetic)
0
insentient(adjective, hard, unfeeling, unsympathetic, hardened)
0
matter of fact(expression, adjective, idiom, callous, unexcitable)
0
poker-faced(adjective, callous, unexcitable)
15 years ago|110 views|share |citing 
APASmart Define. (2011). hard-as-nails thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/hard-as-nails/thesaurus/synonyms
ChicagoSmart Define. 2011. "hard-as-nails thesaurus" https://smartdefine.org/hard-as-nails/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2011, hard-as-nails thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/hard-as-nails/thesaurus/synonyms>.
MLASmart Define. "hard-as-nails thesaurus" 24 May 2011. Web. 28 September 2026. <https://smartdefine.org/hard-as-nails/thesaurus/synonyms>