US politician swindles island, acquiring Greek drugs (11)
I believe the answer is:
congressman
'us politician' is the definition.
(I've seen this before)
'swindles island acquiring greek drugs' is the wordplay.
'swindles' becomes 'cons' ('con' can be a synonym of 'swindle').
'island' becomes 'Man' (the Isle of Man is an example).
'acquiring' means one lot of letters goes inside another.
'greek drugs' becomes 'gres' (I can't explain this - if you can you should give a lot more credence to this answer).
'cons'+'man'='consman'
'consman' going around 'gres' is 'CONGRESSMAN'.
Can you help me to learn more?
(Other definitions for congressman that I've seen before include "Member of US legislature" , "US politician" .)