1
steady(unreliable, untrustworthy)
1
stringent(adjective, rigid, tight)
1
tight
1
unaccommodating(adjective, firm, stiff)
1
unalterable
1
unbendable(adjective, firm, stiff, pliable, velvety)
1
unchangeable
1
unrelenting(adjective, merciless)
1
very angry
1
acerbic
1
ageless
1
all-or-nothing
1
breakable
1
compact
1
concrete(adjective, unimportant, hardened)
1
constant
1
crumbly
1
demanding
1
doctrinaire(adjective, opinionated, dogmatic)
1
dogged
10 years ago|4.5k views|share |citing 
APASmart Define. (2016). flexible thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/flexible/thesaurus/antonyms
ChicagoSmart Define. 2016. "flexible thesaurus" https://smartdefine.org/flexible/thesaurus/antonyms (accessed September 24, 2026).
HarvardSmart Define 2016, flexible thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/flexible/thesaurus/antonyms>.
MLASmart Define. "flexible thesaurus" 28 March 2016. Web. 24 September 2026. <https://smartdefine.org/flexible/thesaurus/antonyms>