Lovely metal link (5)
I believe the answer is:
cutie
'lovely' is the definition.
(I've seen this before)
'metal link' is the wordplay.
'metal' becomes 'cu' (Cu is an example).
'link' becomes 'tie' (synonyms).
'cu'+'tie'='CUTIE'
(Other definitions for cutie that I've seen before include "Attractive person or animal" , "Smart female" , "Smart girl" , "Appealing young lady" , "Smasher" .)