Copper, say, has new mate left (5)
I believe the answer is:
metal
'copper say' is the definition.
(copper is a kind of metal)
'new mate left' is the wordplay.
'new' indicates an anagram.
'left' becomes 'l' (common abbreviation).
'mate' anagrammed gives 'meta'.
'meta'+'l'='METAL'
'has' is the link.
(Other definitions for metal that I've seen before include "Intrinsic quality; stone for roads" , "Zirconium, for example" , "Copper possibly" , "Element eg for road or rail" , "Substance as gold, iron" .)