4
undetermined(adjective, chance 2)
4
unexpected(adjective, careless, chance, casual, arbitrary)
4
unforeseen(adjective, chance, lucky, liable, unplanned)
4
unpremeditated(adjective, careless, chance, casual, random)
3
accident
3
afoot
3
aleatory
3
auxiliary
3
coincidental(adjective, chance, minor, secondary, related)
3
contingency
3
current
3
doing
3
happening
3
hit-or-miss(adjective, careless, chance, casual, random)
3
inadvertent(unintentional, unintended)
3
incidental expense(noun, expression, idiom)
3
inconclusive(adjective, restricted, indirect, provisional, restrictive)
3
indeterminate(adjective, chance 2)
3
item(noun, part, thing, piece, story)
3
lucky(adjective, happy, uncertain, casual, beneficial)
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APASmart Define. (2016). incidental thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/incidental/thesaurus/synonyms
ChicagoSmart Define. 2016. "incidental thesaurus" https://smartdefine.org/incidental/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2016, incidental thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/incidental/thesaurus/synonyms>.
MLASmart Define. "incidental thesaurus" 29 March 2016. Web. 23 September 2026. <https://smartdefine.org/incidental/thesaurus/synonyms>