wanton

 (wänt-n, wȯnt-) (adj)

:manifesting extreme indifference to a risk of injury to another that is known or should have been known

:characterized by knowledge of and utter disregard for probability of resulting harm a ⁓ actby such ⁓ or willful misconduct

see also reckless 

Wantonreckless, and willful are often used to refer to an aggravated level of negligence that borders on intent and that is often ground for an award of punitive damages.

wantonly
advwantonness
n