In favour of nasty drug getting outlawed (7)
I believe the answer is:
forbade
'outlawed' is the definition.
(thesaurus)
'in favour of nasty drug getting' is the wordplay.
'in favour of' becomes 'for' (being for a particular cause).
'nasty' becomes 'bad' (I've seen this in another clue).
'drug' becomes 'e' (E is another name for ecstasy).
'getting' is a charade indicator (letters next to each other).
'for'+'bad'+'e'='FORBADE'
(Other definitions for forbade that I've seen before include "banned" , "Prohibited" , "Disallowed" , "Vetoed" .)