4
vivify(verb, strength, stimulate, strengthen, refresh)
3
acclimatise
3
amalgamate(verb, close, set, meet, develop)
3
animalize(verb, feel, emotions, bad action)
3
bake(verb, close, set, settle, firm)
3
bestialize(verb, feel, emotions, bad action)
3
case harden(expression, idiom, strength)
3
cement(verb, close, set, develop, secure)
3
corrupt(verb, feel, emotions, bad action)
3
debase(verb, feel, emotions, bad action)
3
demoralize(verb, feel, emotions, bad action)
3
densify(verb, close, set, settle, firm)
3
deprave(verb, feel, emotions, bad action)
3
develop(verb, form, study, secure, join)
3
embitter(verb, thicken, stabilize, toughen, season)
3
empower(verb, support, increase, establish, extend)
3
energize(verb, support, increase, raise, stimulate)
3
enliven(verb, encourage, stimulate, restore, strengthen)
3
flanterize(verb, feel, emotions, bad action)
3
go bad(verb, feel, emotions, bad action)
10 years ago|10k views|share |citing 
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>