Helped young Kennedy when underwriting a wager (7)
I believe the answer is:
abetted
'helped young' is the definition.
'abetted' can be an answer for 'helped' (I've seen this in another clue). I'm unsure of the 'young' bit.
'kennedy when underwriting a wager' is the wordplay.
'kennedy when' becomes 'ted' (I can't justify this - if you can you should give a lot more credence to this answer).
'underwriting' means one lot of letters go next to another (some letters written underneath others).
'wager' becomes 'bet' (synonyms).
'a'+'bet'='abet'
'ted' put after 'abet' is 'ABETTED'.
Can you help me to learn more?
(Other definitions for abetted that I've seen before include "Assisted (a felon)" , "Assisted (a criminal)" , "Aided in crime" , "Assisted or encouraged in some wrongdoing" , "Helped (a criminal)" .)