15
by the way(verb, expression, idiom, adverb, phrasal verb)
11
parenthetically(adverb, occasion, aside, irrelation)
10
accidentally
10
casually(adverb, accidentally)
8
en passant(expression, idiom, occasion, intention, irrelation)
7
by the by(verb, expression, idiom, adverb, phrasal verb)
6
by chance(expression, idiom, adverb)
6
apropos
6
occasionally(expression, adverb, time, rare, frequency)
5
in passing(expression, idiom, adverb, aside)
4
circumstantially(adverb, circumstantially)
4
by accident(expression, idiom)
4
fortuitously
4
haphazardly
4
random
4
randomly
3
apart from(adverb, addition, complement, aside, exception)
3
passing
2
accessorily
2
accidental
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APASmart Define. (2015). incidentally thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/incidentally/thesaurus/synonyms
ChicagoSmart Define. 2015. "incidentally thesaurus" https://smartdefine.org/incidentally/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2015, incidentally thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/incidentally/thesaurus/synonyms>.
MLASmart Define. "incidentally thesaurus" 14 April 2015. Web. 21 September 2026. <https://smartdefine.org/incidentally/thesaurus/synonyms>