528 entries under adjective topic. ×

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