Lovable rogue in danger with drug (9)
I believe the answer is:
endearing
'lovable' is the definition.
(similar in meaning)
'rogue in danger with drug' is the wordplay.
'rogue' indicates anagramming the letters (letters go rogue).
'with' means one lot of letters go next to another.
'drug' becomes 'e' (E is another name for ecstasy).
'in'+'danger'='indanger'
'indanger' with letters rearranged gives 'ndearing'.
'ndearing' put after 'e' is 'ENDEARING'.
(Other definitions for endearing that I've seen before include "delightful" , "Disarming" , "Inspiring affection" , "Engaging" , "Charming" .)