10
bestial(adjective, animal, mean, severe, evil)
9
murderous(adjective, hard, tough, harsh, violent)
9
beastly(adjective, mean, violent, cruel, vicious)
9
cold(adjective, mean, hard, tough, severe)
9
cutthroat(adjective, mean, severe, harsh, cruel)
9
dog-eat-dog(adjective, mean, severe, harsh, cruel)
9
fell(adjective, animal, mean, harsh, violent)
9
feral(adjective, mean, violent, cruel, vicious)
9
hardhearted(adjective, mean, severe, harsh, cold)
9
hellish(adjective, evil, nasty, harsh, violent)
9
obdurate(adjective, mean, hard, tough, severe)
9
stony(adjective, mean, hard, tough, severe)
9
stony-hearted(adjective, cold, cruel, unfeeling, unsympathetic)
8
indifferent(adjective, mean, hard, harsh, cold)
8
mean(verb, adjective, animal, hard, severe)
8
monstrous(adjective, severe, evil, nasty, harsh)
8
unbending(adjective, hard, rough, harsh, cruel)
8
uncompromising(adjective, hard, rough, harsh, cruel)
7
atrocious(adjective, evil, nasty, harsh, rude)
7
bloody(adjective, hard, tough, harsh, violent)
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APASmart Define. (2016). ruthless thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/ruthless/thesaurus/synonyms
ChicagoSmart Define. 2016. "ruthless thesaurus" https://smartdefine.org/ruthless/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, ruthless thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/ruthless/thesaurus/synonyms>.
MLASmart Define. "ruthless thesaurus" 24 March 2016. Web. 22 September 2026. <https://smartdefine.org/ruthless/thesaurus/synonyms>