Get better to lay bet off again (7)
I believe the answer is:
recover
I believe this clue is a double definition.
'get better' is the first definition.
(synonyms)
'lay bet off again' is the second definition.
(to lay off a bet is to cover one's losses)
'to' acts as a link.
(Other definitions for recover that I've seen before include "Get well again" , "Rally, get better" , "Find" , "Obtain the return of" , "Recuperate" .)