That Bow lass after wine becomes a fool (7)
I believe the answer is:
plonker
'a fool' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'that bow lass after wine' is the wordplay.
'that bow lass' becomes 'er' (I am not sure about this - if you are sure you should believe this answer much more).
'after' means one lot of letters go next to another.
'wine' becomes 'plonk' (plonk is a kind of wine).
'er' put after 'plonk' is 'PLONKER'.
'becomes' is the link.
Can you help me to learn more?
(Other definitions for plonker that I've seen before include "Fool (slang)" , "Inept person (slang)" , "Stupid person" , "Foolish person - smacking kiss" , "Fool - smacking kiss" .)