9
consolidate(verb, support, close, place, set)
9
fix(verb, close, set, secure, settle)
9
petrify(verb, close, set, hard, settle)
9
steel(verb, support, close, set, increase)
8
acclimatize(verb, close, set, continue, firm)
8
acclimate(verb, close, set, keep, overcome)
8
brutalize(verb, corrupt, feel, strengthen, emotions)
8
clot(verb, form, close, set, develop)
8
confirm(verb, support, strong, increase, establish)
8
invigorate(verb, support, increase, raise, strength)
7
anneal(verb, support, close, set, increase)
7
buttress(verb, support, close, set, increase)
7
compact(verb, close, set, develop, secure)
7
debauch(verb, feel, emotions, bad action)
7
dry(verb, take, close, set, settle)
7
firm(verb, close, set, settle, solid)
7
fossilize(verb, close, set, settle, firm)
7
train(noun, verb, prepare, endure, adjust)
6
concrete(verb, close, set, firm, solid)
6
habituate(verb, study, develop, improve, prepare)
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APASmart Define. (2016). harden thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/harden/thesaurus/synonyms
ChicagoSmart Define. 2016. "harden thesaurus" https://smartdefine.org/harden/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2016, harden thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/harden/thesaurus/synonyms>.
MLASmart Define. "harden thesaurus" 24 March 2016. Web. 25 September 2026. <https://smartdefine.org/harden/thesaurus/synonyms>