For someone who likes a flutter, it's wiser (6)
I believe the answer is:
better
This clue might be a double definition.
'for someone who likes a flutter' is the first definition.
'better' can be an answer for 'for someone' (better is a kind of someone). I am unsure of the rest of the definition.
'wiser' is the second definition.
(thesaurus)
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for better that I've seen before include "On the mend" , "recovering from illness" , "Partly or fully recovered from illness" , "More competent - gambler" , "Recovered; gambler" .)