3
integration(numeration, mixing)
3
involution
3
joining(noun, capture, seizure)
3
more
3
notation
3
over and above(verb, expression, idiom, phrasal verb, preposition)
3
postscript(noun, increase, extra, supplement, additive)
3
practice
3
proliferation(noun, increase, rise, growth, surge)
3
summing-up
3
supplementation
3
tally(noun, mark, total, average, points)
3
totaling(noun, process, calculation, reckoning, adding)
3
upsurge(noun, advance, increase, raise, rise)
2
accord
2
add
2
accident
2
acquirement(noun, gain, achievement, recovery, attainment)
2
additum
2
adjuvant
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APASmart Define. (2015). addition thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/addition/thesaurus/synonyms
ChicagoSmart Define. 2015. "addition thesaurus" https://smartdefine.org/addition/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, addition thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/addition/thesaurus/synonyms>.
MLASmart Define. "addition thesaurus" 22 December 2015. Web. 23 September 2026. <https://smartdefine.org/addition/thesaurus/synonyms>