heedless
HEED-lisadjMeaning paying no attention to warnings or dangers; careless
Memory hook HEED-LESS: pays no heed. Pip pays no heed to the “Wet Paint” sign and sits right down on the bench. He is heedless.
Heedless of the wet-paint sign, Pip plopped down on the bench and ruined his shorts.
In context The young pilot was not brave but heedless: he ignored every storm warning and flew straight into the thunderclouds.
Similar careless, unmindful, reckless, inattentive
Opposite careful, mindful, heedful