3
fake(adjective, free, casual, impulsive, spontaneous)
3
immediate(noun, adjective, free, casual, impulsive)
3
improvisatory(adjective, free, casual, impulsive, impulse)
3
improvise(informal, impulse, unplanned, extemporize, off-the-cuff)
3
involuntary(noun, adjective, simple, passionate, violent)
3
natural(adjective, simple, casual, impulsive, willing)
3
precipitate(noun, thoughtless, impetuous, unwary)
3
quick(noun, thoughtless, impetuous, unwary, transientness)
3
unarranged(adjective, spontaneous, unprepared, unplanned, unrehearsed)
3
unintentional(adjective, simple, natural, chance, casual)
3
unorganized
3
unscripted(adjective, fake, spontaneous, unprepared, impromptu)
2
ad hoc(expression, adjective, idiom, free, informal)
2
brief
2
brisk
2
expedient(adjective, free, casual, impulsive, spontaneous)
2
ill-considered(adjective, impulsive, unprepared)
2
impetuous(noun, adjective, simple, passionate, violent)
2
instantaneous(adjective, impulsive, transientness)
2
reflexive(adjective, impulsive)
11 years ago|9.3k views|share |citing 
APASmart Define. (2015). extemporaneous thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/extemporaneous/thesaurus/synonyms
ChicagoSmart Define. 2015. "extemporaneous thesaurus" https://smartdefine.org/extemporaneous/thesaurus/synonyms (accessed September 28, 2026).
HarvardSmart Define 2015, extemporaneous thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/extemporaneous/thesaurus/synonyms>.
MLASmart Define. "extemporaneous thesaurus" 13 April 2015. Web. 28 September 2026. <https://smartdefine.org/extemporaneous/thesaurus/synonyms>