Fold arrangement with feeble former partner (3,5)
I believe the answer is:
old flame
'former partner' is the definition.
(I've seen this before)
'fold arrangement with feeble' is the wordplay.
'arrangement' is an anagram indicator.
'with' is a charade indicator (letters next to each other).
'feeble' becomes 'lame' (lame can mean feeble or pathetic).
'fold' with letters rearranged gives 'oldf'.
'oldf'+'lame'='OLD FLAME'
(Other definitions for old flame that I've seen before include "Former lover" , "Former sweetheart" , "Ex-lover - the fire still burns" , "Former partner" , "still 1 across [ALIGHT], it seems" .)