62 entries under demanding topic. ×

14
hard(adjective, mean, strong, tough, severe)
14
severe(adjective, person, mean, strong, hard)
12
merciless(adjective, mean, severe, rough, difficult)
10
stern(adjective, tough, severe, firm, harsh)
9
harsh(adjective, mean, strong, hard, tough)
8
strict(adjective, strong, hard, tough, severe)
8
tough(adjective, strong, hard, severe, rough)
7
exacting(adjective, tough, severe, rough, firm)
6
rigorous(adjective, strong, hard, tough, severe)
6
stringent(adjective, tough, severe, firm, harsh)
5
rigid(adjective, strong, hard, tough, severe)
4
rough(adjective, strong, hard, tough, difficult)
3
difficult(adjective, tough, rough, harsh, heavy)
2
burdensome(adjective, tough, rough, difficult, harsh)
2
grinding(adjective, tough, rough, difficult, harsh)
2
laborious(adjective, tough, rough, difficult, heavy)
2
rugged(adjective, strong, hard, tough, severe)
2
strenuous(adjective, tough, rough, difficult, harsh)
1
arduous(adjective, tough, rough, difficult, harsh)
1
backbreaking(adjective, tough, rough, difficult, heavy)
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APASmart Define. (2016). unsparing thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/unsparing/thesaurus/synonyms
ChicagoSmart Define. 2016. "unsparing thesaurus" https://smartdefine.org/unsparing/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2016, unsparing thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/unsparing/thesaurus/synonyms>.
MLASmart Define. "unsparing thesaurus" 24 March 2016. Web. 28 September 2026. <https://smartdefine.org/unsparing/thesaurus/synonyms>