Wrench from the reckless youngster (8)
I believe the answer is:
tearaway
'wrench from the reckless youngster' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'wrench from the reckless youngster' is the wordplay.
'wrench' becomes 'tear' (I've seen this in another clue).
'from' is a charade indicator (letters next to each other).
'the reckless youngster' becomes 'away' (I can't explain this - if you can you should give a lot more credence to this answer).
'tear'+'away'='TEARAWAY'
Can you help me to learn more?
(Other definitions for tearaway that I've seen before include "Unruly youth" , "Unruly, impetuous person" , "Hooligan" , "Reckless and impetuous person" , "Might I stir" .)