7
mortal(adjective, mean, harsh, cruel, determined)
7
not good
7
rough(adjective, person, hard, difficult, harsh)
7
tyrannical(adjective, hard, tough, evil, nasty)
7
uncharitable(adjective, mean, unkind, ungenerous)
6
atrocious(adjective, evil, nasty, harsh, violent)
6
bestial(adjective, severe, evil, nasty, harsh)
6
feral(adjective, mean, harsh, violent, cruel)
6
hostile(adjective, person, feelings, emotions, rocky)
6
inclement(adjective, unpleasant, cruel, vicious, painful)
6
indifferent(adjective, mean, hard, harsh, cold)
6
monstrous(adjective, severe, evil, nasty, harsh)
6
thoughtless(adjective, person, negative)
6
unbending(adjective, hard, rough, harsh, cruel)
6
vengeful(adjective, mean, severe, evil, nasty)
6
violent(adjective, hard, rough, nasty, harsh)
5
adamant(adjective, person, mean, hard, rough)
5
bowelless
5
cold-hearted(adjective, hard, tough, severe, cold)
5
compassionless(adjective, mean, hard, cruel, unfeeling)
10 years ago|15k views|share |citing 
APASmart Define. (2016). merciless thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/merciless/thesaurus/synonyms
ChicagoSmart Define. 2016. "merciless thesaurus" https://smartdefine.org/merciless/thesaurus/synonyms (accessed September 27, 2026).
HarvardSmart Define 2016, merciless thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/merciless/thesaurus/synonyms>.
MLASmart Define. "merciless thesaurus" 31 March 2016. Web. 27 September 2026. <https://smartdefine.org/merciless/thesaurus/synonyms>