113 entries under hard topic. ×

5
jelled(adjective, set, tough, firm)
5
resistant(adjective, strong, tough, fit)
5
stony(adjective, firm, stiff, rigid)
5
unbending(adjective, firm, stiff, tense)
5
unbreakable(adjective, strong, tough, severe)
4
adamantine(adjective, set, strong, severe)
4
broad(adjective, strong, big, heavy)
4
callous(adjective, set, strong, firm)
4
chunky(adjective, big, heavy, deep)
4
congealed(adjective, set, tough, firm)
4
frozen(adjective, firm, stiff, tense)
4
impermeable(adjective, close, set, tough)
4
nonporous(rigid, resistant, impervious, density)
4
rooted(adjective, strong, secure, steady)
4
steely(adjective, firm, stiff, tense)
3
fat(adjective, heavy, deep, round)
3
hardened(adjective, set, strong, tough)
3
inelastic(adjective, tough, severe, firm)
3
rock(adjective, compact, dense, rock-hard)
2
brick wall(expression, adjective, calm, strong)
10 years ago|51k views|share |citing 
APASmart Define. (2016). solid thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/solid/thesaurus/synonyms
ChicagoSmart Define. 2016. "solid thesaurus" https://smartdefine.org/solid/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, solid thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/solid/thesaurus/synonyms>.
MLASmart Define. "solid thesaurus" 29 March 2016. Web. 22 September 2026. <https://smartdefine.org/solid/thesaurus/synonyms>