Energise the rebel, contacting a rich source for stimulant (11)
I believe the answer is:
amphetamine
'for stimulant' is the definition.
(I've seen this before)
'energise the rebel contacting a rich source' is the wordplay.
'energise' becomes 'amp' (I've seen this in another clue).
'the rebel contacting' becomes 'het' (I can't justify this - if you can you should give a lot more credence to this answer).
'rich source' becomes 'mine' (I've seen this before).
'amp'+'het'+'a'+'mine'='AMPHETAMINE'
Can you help me to learn more?
(Other definitions for amphetamine that I've seen before include "Mood-altering drug" , "Stimulant drug" , "speed that's restricted by law" , "Upper" .)