Gambler going to be richer (6,3)
I believe the answer is:
better off
'richer' is the definition.
(I've seen this before)
'gambler going to be' is the wordplay.
'gambler' becomes 'better' (better is a kind of gambler).
'going to' says to put letters next to each other.
'be' becomes 'off' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'better'+'off'='BETTER-OFF'
Can you help me to learn more?
(Other definitions for better off that I've seen before include "in happier financial circumstances" , "with more money" , "having lost less" , "wealthy" , "Richer" .)