Punch crooner for telling lies (7)

I believe the answer is:

fibbing

I'm a little stuck... Click here to teach me more about this clue!

'punch' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe there's a link between them I don't understand?

'crooner for telling lies' is the wordplay.
'crooner' becomes 'Bing' (Bing Crosby).
'for' means one lot of letters go next to another (I've seen this in other clues).
'telling lies' becomes 'fib' (I am not sure about this - if you are sure you should believe this answer much more).
'bing' put after 'fib' is 'FIBBING'.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

Want a hint initially instead of a full solution? Install my app