Love song cut short opening in the same manner (5)
I believe the answer is:
ditto
'in the same manner' is the definition.
'love song cut short opening' is the wordplay.
'love song' becomes 'ditt' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'cut short' means to remove the last letter.
'opening' becomes 'os' (os is a kind of opening).
'os' with its final letter removed is 'o'.
'ditt'+'o'='DITTO'
(Other definitions for ditto that I've seen before include "Same again, indicated by two dots" , "Repeat the word(s) above" , "As per previous" , "As given above" , "couple of marks" .)