Unrestrained, reckless (6)
I believe the answer is:
wanton
I believe this is a double definition.
'unrestrained' is the first definition.
(I've seen this before)
'reckless' is the second definition.
(I've seen this before)
(Other definitions for wanton that I've seen before include "Irresponsible like vandal, lacking proper motives" , "Irresponsible, lacking proper restraint" , "Sexually promiscuous" , "Thoughtlessly and unnecessarily cruel" , "Playful, capricious" .)