2
unaccountable(careless, immoral, thoughtless, reckless, negligent)
2
unclear(adjective, doubtful, vague, hesitant, changeable)
2
uncontrolled
2
undeterminable
2
undetermined(doubtful, vague, hesitant, changeable, unsure)
2
unfaithful(adjective, changeable, fickle, variable, undependable)
2
unhealthy(risky, dangerous, unsafe)
2
unlooked-for
2
unplanned(noun, adjective)
2
unsteadfast
2
unusual(adjective, irregular, unreliable, fanciful, quirky)
2
vacillant(adjective, hesitant)
2
vagrant(unstable, unsettled, variable, erratic, pointless)
2
versatile(unstable, unsettled, variable)
2
wacky(adjective, unusual, strange, silly, crazy)
2
wanton
2
weird(adjective, unusual, strange, crazy, irregular)
2
without warning(expression, extraordinary, wonderful, shocking, astonishing)
1
light(impulsive, explosive)
1
abrupt(passionate, violent, thoughtless, impetuous, unwary)
11 years ago|19k views|share |citing 
APASmart Define. (2015). unpredictable thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/unpredictable/thesaurus/synonyms
ChicagoSmart Define. 2015. "unpredictable thesaurus" https://smartdefine.org/unpredictable/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, unpredictable thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/unpredictable/thesaurus/synonyms>.
MLASmart Define. "unpredictable thesaurus" 13 April 2015. Web. 22 September 2026. <https://smartdefine.org/unpredictable/thesaurus/synonyms>