111 entries under adjective topic. ×

7
unconscious(simple, natural, casual, impulsive)
6
ad hoc(expression, idiom, free, unplanned)
6
ad libitum(expression, idiom, adverb, informal)
6
haphazard(unprepared, accidental, unintended)
6
hasty
5
offhanded
5
extemporized(adverb, informal, unprepared, unplanned)
5
improv(adverb, free, offhand, unprepared)
5
improvise(verb, informal, unplanned, extemporize)
5
impulsive(adverb, simple, natural, chance)
4
abrupt
4
automatic(free, simple, fake, natural)
4
informal(free, casual, impulsive, spontaneous)
4
involuntary(simple, natural, casual, impulsive)
4
snap(free, casual, impulsive, prepared)
4
stopgap
4
unarranged(spontaneous, unprepared, unplanned, unrehearsed)
4
uncontrived(simple, natural, casual, impulsive)
4
uncontrolled(simple, natural, casual, impulsive)
4
unexpected(chance, unqualified, vulnerable, spontaneous)
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APASmart Define. (2016). impromptu thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/impromptu/thesaurus/synonyms
ChicagoSmart Define. 2016. "impromptu thesaurus" https://smartdefine.org/impromptu/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2016, impromptu thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/impromptu/thesaurus/synonyms>.
MLASmart Define. "impromptu thesaurus" 28 January 2016. Web. 24 September 2026. <https://smartdefine.org/impromptu/thesaurus/synonyms>