A smack on the bottom for false charge (1,3,3)

'a smack on the bottom for false charge' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'a smack on the bottom for false charge' is the wordplay.
I cannot quite understand how this works, but
'a' is found in the answer.
'bottom' could be 'bum' (synonyms) and 'bum' is located in the answer.
'charge' could be 'rap' (both can mean blame or responsibility) and 'rap' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?