Promiscuous (6)
I believe the answer is:
wanton
'promiscuous' is the definition.
(I know that promiscuous can be written as wanton)
This is the entire clue.
(Other definitions for wanton that I've seen before include "Wilful - promiscuous" , "(Of violence) deliberate and unprovoked" , "Dissolute - gratuitously cruel" , "Immoral; motiveless" , "Irresponsible, lacking proper restraint" .)