Widow has bet after party (7)
I believe the answer is:
dowager
'widow' is the definition.
(term for an aristocratic widow)
'bet after party' is the wordplay.
'bet' becomes 'wager' (synonyms).
'after' means one lot of letters go next to another.
'party' becomes 'do' (do can informally mean a party).
'wager' after 'do' is 'DOWAGER'.
'has' is the link.
(Other definitions for dowager that I've seen before include "Rich old girl" , "woman of status" , "woman of property?" , "Widow, imposing elderly woman" , "Titled widow" .)