Synonyms|363Antonyms|90|Broader|9Narrower|7Related|1k
1
unforeseen(chance, quick, abrupt, rapid, hasty)
1
unhatched
1
unintentional(adjective, simple, natural, chance, casual)
1
unmade
1
unmanufactured
1
unpremediated(adjective, simple, natural, casual, impulsive)
1
unprimed
1
unprompted(adjective, adverb, simple, natural, casual)
1
unscheduled
1
unsophisticated(adjective, simple, natural, casual, impulsive)
1
up front(expression, adjective, simple, natural, casual)
1
vamp
1
vamped(adjective, adverb, unprepared, unplanned, unrehearsed)
1
voluntary(adjective, simple, natural, casual, impulsive)
1
whipped up(expression, adjective, adverb, unprepared, unplanned)
1
willing(adjective, simple, natural, casual, impulsive)
1
winging it(expression, free, casual, impulsive, unrehearsed)
1
without preparation(expression, idiom, adverb, offhand, extemporaneous)
1
without restraint(expression, adverb, informal, unplanned, extemporize)
0
as one thinks best(expression, idiom, adverb, informal, extemporize)
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ChicagoSmart Define. 2016. "impromptu thesaurus" https://smartdefine.org/impromptu/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, impromptu thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/impromptu/thesaurus/synonyms>.
MLASmart Define. "impromptu thesaurus" 28 January 2016. Web. 21 September 2026. <https://smartdefine.org/impromptu/thesaurus/synonyms>