Bar of metal (5)
I believe the answer is:
ingot
'bar of metal' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ingot that I've seen before include "Mass of unwrought gold, for instance" , "Moulded metal bar" , "Block of cast metal" , "Cast metal brick" , "Bar, often gold" .)