9
inclement(noun, adjective, cruel, merciless, pitilessness)
9
inhumane(adjective, mean, hard, tough, severe)
9
savage(adjective, mean, hard, tough, harsh)
9
unsparing(adjective, mean, severe, harsh, cruel)
9
unsympathetic(adjective, mean, severe, harsh, cruel)
8
dog-eat-dog(adjective, mean, severe, harsh, cruel)
8
unrelenting(adjective, mean, hard, tough, severe)
7
bloodthirsty(adjective, severe, harsh, violent, cruel)
7
brutish(adjective, violent, cruel, vicious, fierce)
7
ferocious(adjective, mean, harsh, violent, cruel)
7
inexorable(adjective, mean, hard, tough, severe)
7
uncharitable(adjective, mean, unkind, heartless, ungenerous)
7
unyielding(adjective, mean, hard, tough, severe)
6
barbarous(adjective, mean, hard, tough, severe)
6
fierce(adjective, mean, hard, tough, severe)
6
implacable(adjective, mean, hard, tough, severe)
6
inhuman(adjective, mean, hard, tough, harsh)
6
unnatural(heartless, malevolence)
6
vicious(adjective, mean, harsh, violent, cruel)
5
barbaric(adjective, violent, cruel, vicious, fierce)
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APASmart Define. (2016). unmerciful thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/unmerciful/thesaurus/synonyms
ChicagoSmart Define. 2016. "unmerciful thesaurus" https://smartdefine.org/unmerciful/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2016, unmerciful thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/unmerciful/thesaurus/synonyms>.
MLASmart Define. "unmerciful thesaurus" 31 March 2016. Web. 24 September 2026. <https://smartdefine.org/unmerciful/thesaurus/synonyms>