Accessory being old remnant remade (8)
I believe the answer is:
ornament
'accessory' is the definition.
(I've seen this before)
'old remnant remade' is the wordplay.
'old' becomes 'o' (abbreviation).
'remade' indicates anagramming the letters.
'remnant' is an anagram of 'rnament'.
'o'+'rnament'='ORNAMENT'
'being' is the link.
(Other definitions for ornament that I've seen before include "A mark of honour" , "accessory" , "Decorative item" , "It's used to adorn" , "deck" .)