Impetuously (6)
I believe the answer is:
rashly
'impetuously' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rashly that I've seen before include "Without caution" , "In intemperate and injudicious manner" , "in reckless fashion" , "In a hasty and foolhardy manner" , "Recklessly" .)