8
impulsive(noun, adjective, extraordinary, careless, wonderful)
8
brisk(adjective, fast, quick, rapid, speedy)
8
short(adjective, adverb, quick, brief, abrupt)
8
startling(adjective, extraordinary, wonderful, affected, shocking)
7
precipitant(adjective, violent, fast, quick, impulsive)
7
sheer(adjective, sharp, vertical)
7
speedy(adjective, fast, quick, abrupt, rapid)
6
abruptly(adverb, short, suddenly, unexpectedly, unawares)
6
accelerated(adjective, fast, abrupt, rapid, swift)
6
dramatic(adjective, moving, affected, exciting, immediate)
6
expeditious(adjective, fast, quick, abrupt, rapid)
6
fleet(adjective, fast, quick, abrupt, rapid)
6
instant(adjective, prompt, irritable, summary, bad-tempered)
6
shocking(adjective, extraordinary, wonderful, astonishing, astounding)
6
snap(noun, adjective)
6
unannounced
6
unplanned(noun, adjective, impulsive, rash, unthinking)
5
momentary(adjective, brief, immediate, instant, transitory)
5
reckless(noun, adjective, careless, casual, quick)
5
snappy(adjective, keen, energetic, violent, active)
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APASmart Define. (2016). sudden thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/sudden/thesaurus/synonyms
ChicagoSmart Define. 2016. "sudden thesaurus" https://smartdefine.org/sudden/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, sudden thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/sudden/thesaurus/synonyms>.
MLASmart Define. "sudden thesaurus" 26 February 2016. Web. 21 September 2026. <https://smartdefine.org/sudden/thesaurus/synonyms>