31
merciless(adjective, mean, hard, kind, tough)
26
ruthless(adjective, mean, hard, tough, severe)
24
cruel(adjective, mean, severe, harsh, violent)
23
pitiless(adjective, mean, hard, kind, tough)
17
unpitying(noun, adjective, mean, severe, harsh)
16
callous(adjective, mean, severe, harsh, cruel)
16
heartless(adjective, mean, severe, harsh, cruel)
16
remorseless(adjective, mean, hard, kind, severe)
15
brutal(adjective, mean, severe, harsh, violent)
15
unfeeling(adjective, mean, severe, harsh, cruel)
14
uncompassionate(adjective, mean, hard, tough, harsh)
13
hard(adjective, mean, tough, severe, harsh)
13
relentless(adjective, mean, hard, tough, severe)
12
harsh(adjective, mean, hard, tough, severe)
11
cutthroat(adjective, mean, severe, harsh, cruel)
11
hardhearted(adjective, mean, severe, harsh, cruel)
11
unforgiving(adjective, mean, hard, tough, severe)
11
unkind(adjective, mean, severe, harsh, cruel)
9
cold-blooded(adjective, mean, harsh, cruel, vicious)
9
hard-hearted(adjective, mean, hard, tough, harsh)
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APASmart Define. (2016). unmerciful thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/unmerciful/thesaurus/synonyms
ChicagoSmart Define. 2016. "unmerciful thesaurus" https://smartdefine.org/unmerciful/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, unmerciful thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/unmerciful/thesaurus/synonyms>.
MLASmart Define. "unmerciful thesaurus" 31 March 2016. Web. 21 September 2026. <https://smartdefine.org/unmerciful/thesaurus/synonyms>