122 entries under harden topic. ×

32
reinforce(verb, support, hold, close, get)
31
fortify(verb, form, support, make, close)
28
brace(noun, verb, form, support, hold)
19
buttress(noun, verb, support, hold, close)
17
increase(noun, verb, support, get, charge)
16
toughen(verb, support, close, set, fix)
14
steel(verb, form, support, make, dull)
11
temper(verb, close, set, fix, encourage)
10
develop(verb, form, support, make, dull)
10
prop(verb, support, hold, help, fix)
10
shore up(verb, expression, phrasal verb, support, help)
9
augment(verb, support, get, help, advance)
9
beef up(verb, expression, phrasal verb, support, increase)
9
build up(verb, expression, phrasal verb, form, support)
9
consolidate(verb, support, close, set, fix)
9
gird(verb, form, support, make, close)
8
nerve(verb, close, set, fix, encourage)
8
stiffen(verb, support, dull, close, set)
5
anneal(verb, close, set, fix, settle)
4
condense(verb, develop, secure, join, unite)
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APASmart Define. (2016). strengthen thesaurus. Retrieved September 30, 2026, from https://smartdefine.org/strengthen/thesaurus/synonyms
ChicagoSmart Define. 2016. "strengthen thesaurus" https://smartdefine.org/strengthen/thesaurus/synonyms (accessed September 30, 2026).
HarvardSmart Define 2016, strengthen thesaurus, Smart Define, viewed 30 September, 2026, <https://smartdefine.org/strengthen/thesaurus/synonyms>.
MLASmart Define. "strengthen thesaurus" 3 March 2016. Web. 30 September 2026. <https://smartdefine.org/strengthen/thesaurus/synonyms>