Average doctor gains energy during ramble (7)
I believe the answer is:
meander
'ramble' is the definition.
(I know that ramble can be written as meander)
'average doctor gains energy during' is the wordplay.
'average' becomes 'mean' (type of average).
'doctor' becomes 'dr' (abbreviation).
'gains' is a charade indicator (letters next to each other).
'energy' becomes 'e' (physics symbol as in E=mcr).
'during' is an insertion indicator.
'mean'+'dr'='meandr'
'meandr' placed around 'e' is 'MEANDER'.
(Other definitions for meander that I've seen before include "Wind (like a river)" , "Dear men (anag) - wander" , "Red mane (anag) - roam aimlessly" , "Wander about, follow a winding course" , "Indirectly move" .)