170 entries under verb topic. ×

17
strengthen(support, close, set, fix)
14
brace(support, close, set, fix)
13
harden(support, close, set, increase)
12
fortify(support, close, set, fix)
11
reinforce(support, close, set, fix)
10
temper(noun, close, set, fix)
9
acclimate(close, set, keep, overcome)
9
acclimatize(close, set, fix, continue)
8
anneal(support, close, set, fix)
7
confirm(support, increase, establish, extend)
7
invigorate(support, increase, encourage, establish)
7
season(close, set, keep, overcome)
7
stiffen(support, close, set, fix)
6
indurate(close, set, fix, settle)
6
inure(rough, prepare, strengthen, scratch)
5
accustom(rough, prepare, adjust, scratch)
5
buttress(support, close, set, fix)
5
callous(adjective, close, set, fix)
5
support(increase, establish, extend, sustain)
4
develop(strengthen, scratch, harden, roughen)
<12345…9>
11 years ago|4.3k views|share |citing 
APASmart Define. (2015). toughen thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/toughen/thesaurus/synonyms
ChicagoSmart Define. 2015. "toughen thesaurus" https://smartdefine.org/toughen/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2015, toughen thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/toughen/thesaurus/synonyms>.
MLASmart Define. "toughen thesaurus" 13 April 2015. Web. 28 September 2026. <https://smartdefine.org/toughen/thesaurus/synonyms>