150 entries under grim topic. ×

15
unremitting(adjective, hard, tough, harsh, determined)
14
dogged(adjective, appearance, mean, hard, tough)
14
ruthless(adjective, animal, appearance, mean, hard)
13
iron(noun, adjective, mean, hard, tough)
13
merciless(adjective, appearance, mean, hard, tough)
12
stiff-necked(adjective, mean, strong, hard, tough)
11
pertinacious(adjective, strong, tough, cold, determined)
11
pitiless(adjective, animal, mean, hard, tough)
11
tough(adjective, mean, strong, hard, severe)
10
unmerciful(adjective, mean, hard, tough, severe)
9
mulish(adjective, mean, strong, hard, tough)
8
hardheaded(adjective, strong, hard, tough, cold)
8
savage(adjective, animal, mean, hard, tough)
7
austere(adjective, appearance, strong, hard, tough)
7
headstrong(adjective, strong, tough, firm, cold)
7
inhuman(adjective, animal, mean, hard, tough)
7
pigheaded(adjective, mean, hard, tough, firm)
7
rough(adjective, strong, hard, tough, severe)
6
hardened(adjective, hard, tough, harsh, determined)
6
intractable(adjective, appearance, strong, tough, firm)
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APASmart Define. (2015). unrelenting thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/unrelenting/thesaurus/synonyms
ChicagoSmart Define. 2015. "unrelenting thesaurus" https://smartdefine.org/unrelenting/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2015, unrelenting thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/unrelenting/thesaurus/synonyms>.
MLASmart Define. "unrelenting thesaurus" 3 August 2015. Web. 28 September 2026. <https://smartdefine.org/unrelenting/thesaurus/synonyms>