57
merciless(adjective, appearance, mean, hard, tough)
56
cruel(adjective, appearance, mean, hard, tough)
46
pitiless(adjective, animal, mean, hard, tough)
40
savage(adjective, animal, mean, hard, tough)
38
brutal(adjective, mean, hard, tough, severe)
28
inhuman(adjective, animal, mean, hard, tough)
27
harsh(adjective, mean, hard, tough, severe)
25
heartless(adjective, mean, feeling, hard, tough)
25
unmerciful(adjective, mean, hard, tough, severe)
22
barbarous(adjective, animal, appearance, mean, hard)
22
remorseless(adjective, animal, mean, severe, harsh)
21
callous(adjective, mean, hard, tough, severe)
21
unfeeling(adjective, animal, mean, severe, evil)
20
cold-blooded(adjective, mean, hard, tough, severe)
20
hard(adjective, mean, tough, severe, evil)
20
relentless(adjective, animal, appearance, mean, hard)
19
unsympathetic(adjective, animal, mean, hard, tough)
19
ferocious(adjective, animal, mean, hard, evil)
18
fierce(adjective, animal, mean, hard, tough)
18
unrelenting(adjective, animal, appearance, mean, hard)
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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>