Heedless means taking no notice of danger or advice. Heedless of the warning, heedless haste, ride on heedless.
It is literary and nearly always followed by of. The heed inside it is a verb that still just survives in take heed and heed a warning, but heedless is now much commoner than the positive form.
1adjectiveheedlessTaking no notice of danger or advice.
“Heedless of the warnings, the boys swam out past the red flags.”
heedless is a quality.
Proto-Indo-European
*kadʰ- — to heed, protect
Proto-West Germanic
*hōdijan — to heed, guard
Old English
hēdan — to heed, take care, observe, attend, guard, take charge, take possession, receive
Middle English
heden
English
heed
English, today
heedless
From heed + -less. heed comes from Middle English heden, from Old English hēdan (“to heed, take care, observe, attend, guard, take charge, take possession, receive”), from Proto-West Germanic hōdijan (“to heed, guard”), from Proto-Indo-European kadʰ- (“to heed, protect”). Cognate with West Frisian hoedje (“to heed”), Dutch hoeden (“to heed”), German hüten (“to heed”).
Etymology from Wiktionary, CC BY-SA