5
accessory(noun, extra, addition, attachment, decoration)
5
supplement(noun, increase, extra, addition, attachment)
4
addition(noun, increase, extra, attachment, decoration)
4
appurtenance(noun, extra, addition, attachment, decoration)
4
extension(noun, increase, treat, extra, extravagance)
3
improver
2
adjunct(noun, increase, extra, addition, attachment)
2
extra(noun, adjective, increase, addition, additional)
1
accoutrement(noun, extra, addition)
1
addendum(noun, increase, extra, addition, attachment)
1
additive(noun, increase, extra, addition, ingredient)
1
affix(noun, addition, supplement)
1
after-market item
1
appendage(noun, increase, extra, addition, attachment)
1
appendix(noun, increase, extra, addition, attachment)
1
attached item
1
attachment(noun, extra, addition, decoration, supplement)
1
gain(noun, extra, supplement, appendage)
1
postscript(noun, increase, extra, addition, supplement)
1
suffix
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APASmart Define. (2015). add-on thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/add-on/thesaurus/synonyms
ChicagoSmart Define. 2015. "add-on thesaurus" https://smartdefine.org/add-on/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, add-on thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/add-on/thesaurus/synonyms>.
MLASmart Define. "add-on thesaurus" 22 December 2015. Web. 21 September 2026. <https://smartdefine.org/add-on/thesaurus/synonyms>