A fence I mended for a partner (7)
I believe the answer is:
fiancee
'for a partner' is the definition.
(I have seen 'Future partner' mean 'fiancee' so perhaps 'partner' could also mean 'fiancee')
'a fence i mended' is the wordplay.
'mended' is an anagram indicator.
'a'+'fence'+'i'='afencei'
'afencei' with letters rearranged gives 'FIANCEE'.
(Other definitions for fiancee that I've seen before include "ringed girl" , "Betrothed woman" , "Bride-to-be" , "Future partner" , "Promised" .)