75 entries under tough topic. ×

13
uncompassionate(adjective, animal, mean, hard)
13
unforgiving(adjective, person, mean, hard)
12
inexorable(adjective, mean, hard, severe)
12
stony(adjective, mean, hard, severe)
11
cold(adjective, mean, hard, severe)
11
murderous(adjective, hard, harsh, violent)
11
unrelenting(adjective, animal, mean, hard)
10
implacable(adjective, animal, mean, hard)
10
insensitive(adjective, hard, severe, harsh)
10
obdurate(adjective, mean, hard, severe)
8
grim(adjective, animal, mean, hard)
7
tyrannical(adjective, hard, nasty, harsh)
7
unyielding(adjective, mean, hard, severe)
5
sanguinary(adjective, hard, harsh, violent)
4
cold-hearted(adjective, hard, severe, cold)
4
uncaring(adjective, person, hard, severe)
3
apathetic(adjective, hard, severe, cold)
3
bloody(adjective, hard, harsh, violent)
3
exacting(adjective, hard, severe, harsh)
3
insensible(adjective, hard, severe, care)
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APASmart Define. (2016). pitiless thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/pitiless/thesaurus/synonyms
ChicagoSmart Define. 2016. "pitiless thesaurus" https://smartdefine.org/pitiless/thesaurus/synonyms (accessed September 26, 2026).
HarvardSmart Define 2016, pitiless thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/pitiless/thesaurus/synonyms>.
MLASmart Define. "pitiless thesaurus" 24 March 2016. Web. 26 September 2026. <https://smartdefine.org/pitiless/thesaurus/synonyms>