Recovered teetotaller stopping alcohol (6)
I believe the answer is:
better
'recovered' is the definition.
(I've seen this before)
'teetotaller stopping alcohol' is the wordplay.
'teetotaller' becomes 'tt' (abbreviation).
'stopping' means one lot of letters goes inside another (stopping can mean blocking a gap).
'alcohol' becomes 'beer' (beer is a kind of alcohol).
'tt' inserted inside 'beer' is 'BETTER'.
(Other definitions for better that I've seen before include "More able" , "On the mend" , "Speculator" , "Surpass; gambler" , "Superior; gambler" .)