Joint freer after manipulation, if energy put in (6)
I believe the answer is:
reefer
'joint' is the definition.
(informal term for a marijuana joint)
'freer after manipulation if energy put in' is the wordplay.
I cannot really understand how this works, but
'energy' could be 'e' (physics symbol as in E=mc2) and 'e' is present in the answer.
an anagram of 'freer' is 'refer' which is within the left over letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for reefer that I've seen before include "courses may be reduced by one" , "Smoking jacket and cigarette" , "Warm jacket - cannabis cigarette" , "drugged cigarette" , "Jacket - joint - cargo vehicle" .)