Bash and jab tender part of body at first (7)
I believe the answer is:
shindig
'bash' is the definition.
(I've seen this before)
'and jab tender part of body at first' is the wordplay.
'and' becomes 'n' (common abbreviation for 'and').
'jab' becomes 'dig' (both can mean a hurtful comment).
'tender part of body' becomes 'shi' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'at first' means one lot of letters go next to another.
'n'+'dig'='ndig'
'ndig' after 'shi' is 'SHINDIG'.
Can you help me to learn more?
(Other definitions for shindig that I've seen before include "wild party" , "Noisy knees-up" , "Rumpus" , "Lively party, knees-up" , "Lively celebration (informal)" .)