5
broaden(verb, take, cover, advance, increase)
5
heighten(verb, take, cover, advance, increase)
5
reinforcement(noun, extra, addition, complement, appendage)
5
strengthen(verb, support, help, advance, increase)
5
widen(verb, take, cover, advance, increase)
4
accompany(verb, complete, enhance, add, accompany)
4
additive(noun, increase, extra, addition, ingredient)
4
annexe(noun, adjunct)
4
contribution(noun, influence, say, gift, role)
4
garnish(verb, accompany, accessory, adjunct)
4
insert(noun, verb, increase, attach, enhance)
4
magnify(verb, take, cover, advance, increase)
4
raise(noun, verb, advance, increase, rise)
4
rider(noun, act, increase, measure, extra)
3
accoutrement(noun, part, extra, addition, extension)
3
amendment(noun, act, measure, qualification, provision)
3
annexation
3
complete(verb, close, part, end, agree)
3
concomitant
3
continuance(noun, extension, persistence)
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APASmart Define. (2015). supplement thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/supplement/thesaurus/synonyms
ChicagoSmart Define. 2015. "supplement thesaurus" https://smartdefine.org/supplement/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, supplement thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/supplement/thesaurus/synonyms>.
MLASmart Define. "supplement thesaurus" 22 December 2015. Web. 21 September 2026. <https://smartdefine.org/supplement/thesaurus/synonyms>