8
transitory(adjective, transient, short-lived)
8
volatile(adjective, capricious, irresolute)
7
changeable(adjective, loose, short, unpredictable, unreliable)
7
flitting(adjective, capricious, irresolute)
7
fugacious(adjective, short, brief, temporary, transient)
7
shifty(adjective, false, dishonest, deceitful, dubious)
7
slippery(adjective, bad, wrong, informal, false)
7
treacherous(adjective, false, dishonest, deceitful, dubious)
7
vagabond(adjective, moving, idle, unsettled, exile)
6
capricious(adjective, false, careless, loose, foolish)
6
trustless(adjective, uncertain, dishonest, doubtful, deceitful)
5
erratic(adjective, loose, unpredictable, unreliable, fickle)
5
uncertain(adjective, nervous, doubtful, dubious, unpredictable)
4
impulsive(adjective, capricious, irresolute)
4
inconstant(adjective, loose, unpredictable, unreliable, fickle)
4
mutable
4
perishable(adjective, transient, transitory, short-lived)
4
short-term
4
temporal
4
unstable(adjective, careless, loose, foolish, uncertain)
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APASmart Define. (2016). fly-by-night thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/fly-by-night/thesaurus/synonyms
ChicagoSmart Define. 2016. "fly-by-night thesaurus" https://smartdefine.org/fly-by-night/thesaurus/synonyms (accessed September 27, 2026).
HarvardSmart Define 2016, fly-by-night thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/fly-by-night/thesaurus/synonyms>.
MLASmart Define. "fly-by-night thesaurus" 26 February 2016. Web. 27 September 2026. <https://smartdefine.org/fly-by-night/thesaurus/synonyms>