Taking drugs at party, one in Papua New Guinea (6)
I believe the answer is:
doping
'taking drugs' is the definition.
(doping is a kind of taking drugs)
'at party one in papua new guinea' is the wordplay.
'at' says to put letters next to each other.
'party' becomes 'do' (do is a kind of party).
'one in papua new guinea' becomes 'ping' (I can't justify this - if you can you should give a lot more credence to this answer).
'do' put next to 'ping' is 'DOPING'.
Can you help me to learn more?
(Other definitions for doping that I've seen before include "Giving sedative" , "Taking 8" .)