65 entries under spontaneous topic. ×

18
extemporaneous(adjective, simple, informal, natural, chance)
16
unrehearsed(adjective, adverb, free, impulsive, prepared)
12
impromptu(adjective, free, simple, fake, informal)
8
extempore(adjective, free, simple, fake, informal)
8
offhand(adjective, free, simple, fake, natural)
8
unprepared(adjective, free, ready, unprepared)
7
ad-lib(adjective, adverb, free, simple, fake)
7
extemporary(adjective, free, casual, impulsive, prepared)
6
off-the-cuff(adjective, adverb, simple, informal, natural)
6
unplanned(adjective, free, simple, fake, informal)
6
unpremeditated(adjective, free, casual, impulsive, impulse)
5
casual(adjective, free, simple, fake, natural)
5
extemporized(adjective, informal, unplanned, unrehearsed)
5
snap(adjective, free, casual, impulsive, impulse)
4
impulsive(adjective, adverb, simple, natural, chance)
4
unstudied(adjective, free, simple, fake, natural)
3
improvisatory(adjective, free, casual, impulsive, impulse)
3
spur-of-the-moment(adjective, free, prepared, unprepared)
3
unscripted(adjective, unprepared, impromptu, unplanned)
2
automatic(adjective, free, simple, fake, natural)
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APASmart Define. (2015). improvised thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/improvised/thesaurus/synonyms
ChicagoSmart Define. 2015. "improvised thesaurus" https://smartdefine.org/improvised/thesaurus/synonyms (accessed September 27, 2026).
HarvardSmart Define 2015, improvised thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/improvised/thesaurus/synonyms>.
MLASmart Define. "improvised thesaurus" 13 April 2015. Web. 27 September 2026. <https://smartdefine.org/improvised/thesaurus/synonyms>