The brat is playin' for money (5)
I believe the answer is:
gamin
'the brat' is the definition.
(thesaurus)
'playin' for money' is the wordplay.
I cannot quite understand how this works, but
'money' could be 'm' (abbreviation in economics) and 'm' is present in the answer.
The remaining letters 'gain' 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).
'is' is the link.
Can you help me to learn more?
(Other definitions for gamin that I've seen before include "Little urchin" , "Street urchin or impudent child" , "Waif" , "stray" , "Little devil" .)