6
rigorous(adjective, strong, hard, tough, severe)
6
stringent(adjective, tough, severe, firm, harsh)
6
unrelenting(adjective, mean, strong, hard, tough)
6
unsympathetic(adjective, person, mean, tough, severe)
5
austere(adjective, strong, hard, tough, severe)
5
brutal(adjective, person, tough, severe, harsh)
5
copious(adjective, grand, extravagant, generous, lavish)
5
hard-hearted
5
heartless(adjective, mean, severe, harsh, cruel)
5
hospitable(adjective, good, kind, reasonable, fair)
5
inflexible(adjective, strong, hard, tough, severe)
5
large(adjective, substantial, generous)
5
obdurate(adjective, close, strong, hard, tough)
5
open
5
plentiful(adjective, substantial, grand, extravagant, generous)
5
rigid(adjective, strong, hard, tough, severe)
5
too-generous
5
unfeeling(adjective, person, mean, tough, severe)
4
benevolent(adjective, good, kind, reasonable, fair)
4
bighearted(kind, generous, prodigal)
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APASmart Define. (2016). unsparing thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/unsparing/thesaurus/synonyms
ChicagoSmart Define. 2016. "unsparing thesaurus" https://smartdefine.org/unsparing/thesaurus/synonyms (accessed September 26, 2026).
HarvardSmart Define 2016, unsparing thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/unsparing/thesaurus/synonyms>.
MLASmart Define. "unsparing thesaurus" 24 March 2016. Web. 26 September 2026. <https://smartdefine.org/unsparing/thesaurus/synonyms>