210 entries under hard topic. ×

24
implacable(adjective, mean, strong, tough)
23
intractable(adjective, strong, tough, rough)
23
hard-nosed(adjective, mean, strong, secure)
23
severe(adjective, strong, tough, severe)
21
dogged(adjective, mean, strong, tough)
21
mulish(adjective, mean, strong, tough)
20
inelastic(adjective, tough, firm, solid)
20
stern(adjective, tough, severe, rough)
19
strict(adjective, strong, tough, moderate)
16
grim(adjective, strong, tough, severe)
16
rigorous(adjective, strong, tough, severe)
15
harsh(adjective, mean, strong, tough)
15
iron(adjective, mean, strong, tough)
15
pigheaded(adjective, mean, firm, deliberate)
15
stony(adjective, person, firm, solid)
13
headstrong(adjective, strong, tough, rough)
13
steely(adjective, strong, tough, firm)
13
unalterable(adjective, set, strong, secure)
12
refractory(adjective, tough, rough, firm)
12
set in stone(expression, adjective, idiom, mean)
10 years ago|28k views|share |citing 
APASmart Define. (2016). inflexible thesaurus. Retrieved September 29, 2026, from https://smartdefine.org/inflexible/thesaurus/synonyms
ChicagoSmart Define. 2016. "inflexible thesaurus" https://smartdefine.org/inflexible/thesaurus/synonyms (accessed September 29, 2026).
HarvardSmart Define 2016, inflexible thesaurus, Smart Define, viewed 29 September, 2026, <https://smartdefine.org/inflexible/thesaurus/synonyms>.
MLASmart Define. "inflexible thesaurus" 24 March 2016. Web. 29 September 2026. <https://smartdefine.org/inflexible/thesaurus/synonyms>