Getting behind wheel with added energy (8)
I believe the answer is:
deriving
'getting behind' is the definition.
Although both the answer and definition are present participle verbs, I can't understand how they can define each other.
'wheel with added energy' is the wordplay.
'wheel' becomes 'driving wheel' (driving wheel is a kind of wheel).
'with' indicates putting letters inside.
'added energy' becomes 'e' (physics symbol as in E=mc2. I am not sure about the 'added' bit.).
'driving' enclosing 'e' is 'DERIVING'.
Can you help me to learn more?
(Another definition for deriving that I've seen is " Drawing (one thing from another)".)