3
uncongenial(adjective, coldhearted)
3
unflinching(adjective, mean, harsh, cruel, determined)
3
ungracious
2
abusive
2
aggressive(adjective, nasty, violent, cruel, vicious)
2
austere(adjective, appearance, hard, severe, harsh)
2
bad(adjective, evil, unpleasant, corrupt, vicious)
2
bitter(adjective, evil, nasty, harsh, unpleasant)
2
blank(adjective, person, feelings, emotions, rocky)
2
cool
2
deadly
2
demanding(adjective, tough, severe, rough, difficult)
2
depraved(adjective, evil, nasty, harsh, corrupt)
2
disagreeable(adjective, unpleasant, vicious, painful, distressing)
2
distressing(adjective, tough, severe, rough, difficult)
2
dogged(adjective, appearance, harsh, terrible, cruel)
2
expressionless(adjective, person, feelings, emotions, rocky)
2
forbidding(adjective, person, appearance, hard, tough)
2
foul(adjective, wicked)
2
grisly(adjective, appearance, terrible, hopeless)
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APASmart Define. (2016). merciless thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/merciless/thesaurus/synonyms
ChicagoSmart Define. 2016. "merciless thesaurus" https://smartdefine.org/merciless/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2016, merciless thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/merciless/thesaurus/synonyms>.
MLASmart Define. "merciless thesaurus" 31 March 2016. Web. 28 September 2026. <https://smartdefine.org/merciless/thesaurus/synonyms>