heedlessness
heed-less-ness
noun
The state of lacking care or attention; failing to consider potential dangers or consequences.
"His heedlessness led to the unfortunate accident."
Thesaurus
Synonyms: rashness, mindlessness, unmindfulness, inadvertence, inadvertency, inattentiveness
Antonyms: attentiveness, heed, heedfulness, mindfulness, paying attention, regard