4
negligent(adjective, happy, careless, superficial, flippant)
4
remiss(adjective, happy, careless, careful, thoughtless)
4
superficial(adjective, happy, sensible, careless, deep)
4
tactless(adjective, careless, unthinking, tactful)
4
uncivil(adjective, happy, careless, superficial, flippant)
4
unthoughtful(adjective, happy, careless, safe, tactful)
3
automatic
3
foolish(adjective, sound, wise, nonsensical, idiotic)
3
haphazard
3
hasty(kind, slow)
3
idiotic(adjective, reasonable, smart, happy, careless)
3
impolite(adjective, happy, careless, superficial, flippant)
3
mad
3
mean(verb, adjective, happy, careless, superficial)
3
random
3
stupid(adjective, sharp, happy, careless, intelligent)
3
unconsidered
3
unheeding
3
unkind(adjective, gentle, friendly)
3
unmannerly(adjective, happy, careless, superficial, flippant)
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APASmart Define. (2016). thoughtful thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/thoughtful/thesaurus/antonyms
ChicagoSmart Define. 2016. "thoughtful thesaurus" https://smartdefine.org/thoughtful/thesaurus/antonyms (accessed September 25, 2026).
HarvardSmart Define 2016, thoughtful thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/thoughtful/thesaurus/antonyms>.
MLASmart Define. "thoughtful thesaurus" 29 March 2016. Web. 25 September 2026. <https://smartdefine.org/thoughtful/thesaurus/antonyms>