1
affix(verb, place, set, fix, secure)
1
amalgamate(verb, close, set, fix, settle)
1
amplify
1
anchor(verb, place, set, fix, secure)
1
angel(verb, keep, maintain, encourage, raise)
1
anneal(verb, close, set, fix, settle)
1
attach(verb, place, set, fix, secure)
1
attend to(verb, expression, keep, maintain, encourage)
1
augment(verb, support, increase, sustain, uphold)
1
back up(verb, expression, support, increase, sustain)
1
bake(verb, close, set, fix, settle)
1
bankroll(verb, keep, maintain, encourage, raise)
1
be a source of strength(verb, keep, maintain, encourage, raise)
1
be tough
1
become rigid(verb, expression, harden, thicken, solidify)
1
bind(verb, place, set, fix, secure)
1
bite(freeze, chill, harden, nip, solidify)
1
blunt(verb, dull, develop, rough, adjust)
1
bolster(verb, support, increase, sustain, uphold)
1
boost(verb, support, increase, sustain, uphold)
11 years ago|7.2k views|share |citing 
APASmart Define. (2015). stiffen thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/stiffen/thesaurus/synonyms
ChicagoSmart Define. 2015. "stiffen thesaurus" https://smartdefine.org/stiffen/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2015, stiffen thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/stiffen/thesaurus/synonyms>.
MLASmart Define. "stiffen thesaurus" 13 April 2015. Web. 25 September 2026. <https://smartdefine.org/stiffen/thesaurus/synonyms>