He has impact in children's entertainment (5)
I believe the answer is:
punch
'entertainment' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'he has impact in children's' is the wordplay.
I cannot quite understand how this works, but
'children' could be 'ch' (genealogical abbreviation) and 'ch' is found within the answer.
The remaining letters 'pun' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for punch that I've seen before include "Strike; former magazine" , "Poke" , "that would be attached to haywain for pulling?" , "horse to get > drink" , "Act violently" .)