1
at short notice(expression, idiom)
1
at sight
1
at will(expression, adverb, informal, unplanned, extemporize)
1
automatically(adverb, spontaneously, improv, extemporaneously)
1
autoschediastic(free, casual, impulsive, spontaneous, unprepared)
1
break loose(expression, adjective, simple, natural, casual)
1
cadenza
1
careless
1
caught napping
1
caught off balance(expression, idiom)
1
caught off guard(expression, idiom, unqualified, unsuspecting, unready)
1
caught short
1
dashed off(expression, adjective, adverb, mock, affected)
1
down(adjective, simple, natural, casual, impulsive)
1
expedient(free, casual, impulsive, spontaneous, unprepared)
1
extemporaneousness
1
extemporariness
1
extemporize(verb, adjective, informal, unplanned, off-the-cuff)
1
faked(adjective, adverb, mock, affected, unprepared)
1
flash
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APASmart Define. (2016). impromptu thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/impromptu/thesaurus/synonyms
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>