5
stony(adjective, hard, firm, stiff, rigid)
5
straight(adjective, open, direct, honest, modest)
5
substantive(adjective, physical, material, substantial, actual)
5
unalloyed(adjective, complete, continuous, closed, blocked)
5
unbending(adjective, hard, firm, stiff, tense)
5
unbreakable(adjective, strong, hard, tough, severe)
5
unchangeable(adjective, calm, strong, secure, firm)
5
uncut(adjective, complete)
5
unified(adjective, complete, simple, whole, consistent)
5
uninterrupted(verb, adjective, sound, complete, smooth)
5
viscid
5
viscous
5
well-constructed(complete, vigorous, sturdy)
5
well-grounded(adjective, good, sound, right, reasonable)
4
accomplished(adjective, cool, great, complete, knowledge)
4
adamant(adjective, rigid)
4
adamantine(adjective, set, strong, hard, severe)
4
appreciable(adjective, substantial)
4
beefy(adjective, person, body, big, heavy)
4
believable(open, honest, sensible, realistic, reliable)
10 years ago|51k views|share |citing 
APASmart Define. (2016). solid thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/solid/thesaurus/synonyms
ChicagoSmart Define. 2016. "solid thesaurus" https://smartdefine.org/solid/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, solid thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/solid/thesaurus/synonyms>.
MLASmart Define. "solid thesaurus" 29 March 2016. Web. 21 September 2026. <https://smartdefine.org/solid/thesaurus/synonyms>