Well, someone having a flutter? (6)
I believe the answer is:
better
I believe this clue is a double definition.
'well' is the first definition.
(similar in meaning)
'someone having a flutter?' is the second definition.
(to have a flutter is to put a bet on)
(Other definitions for better that I've seen before include "cap" , "Preferable" , "recovering from illness" , "Person taking a risk" , "Comparatively good" .)