Girl ends love affair with charm (7)
I believe the answer is:
glamour
'charm' is the definition.
(glamouring is a kind of charming)
'girl ends love affair' is the wordplay.
'ends' suggests removing the centre.
'love affair' becomes 'amour' (I've seen this before).
'girl' with its centre taken out is 'gl'.
'gl'+'amour'='GLAMOUR'
'with' is the link.
(Other definitions for glamour that I've seen before include "Groomed beauty, allure" , "Alluring quality" , "Glitz" , "sophisticated style" , "Alluring beauty, very sexy" .)