5
unreflective(casual, inattention, obtuse, happy-go-lucky, slapdash)
5
unsolicitous(adjective, cold, forget, uncaring, inattentive)
5
unthankful(adjective, thankless, ungrateful)
5
wanton(adjective, free, careless, wild, reckless)
4
absentminded(adjective, careless, indifferent, apathetic, unconcerned)
4
carefree(adjective, feature, state, careless, indifferent)
4
easygoing(adjective, feature, state, dull, careless)
4
free and easy(expression, adjective, idiom, feature, state)
4
harebrained(adjective, careless, wild, silly, stupid)
4
headlong(adjective, violent, careless, fast, quick)
4
insensible(adjective, indifferent, unconcerned, unsympathetic, ignorant)
4
lazy(adjective, slow, careless, indifferent, thoughtless)
4
mooning(adjective, careless, silly, foolish, remote)
4
napping(adjective, careless, casual, thoughtless, inattentive)
4
nearsighted(adjective, dull, careless, indifferent, thoughtless)
4
senseless(adjective, careless, silly, foolish, thoughtless)
4
silly(adjective, careless, foolish, crazy, senseless)
4
slapdash(adjective, careless, indifferent, casual, quick)
4
temerarious(adjective, careless, wild, foolish, thoughtless)
4
unappreciative(adjective, thankless, ungrateful)
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APASmart Define. (2016). heedless thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/heedless/thesaurus/synonyms
ChicagoSmart Define. 2016. "heedless thesaurus" https://smartdefine.org/heedless/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, heedless thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/heedless/thesaurus/synonyms>.
MLASmart Define. "heedless thesaurus" 24 March 2016. Web. 21 September 2026. <https://smartdefine.org/heedless/thesaurus/synonyms>