Gold bar (5)
I believe the answer is:
ingot
'gold bar' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ingot that I've seen before include "Bar of bullion, for example" , "Mass of unwrought gold, for instance" , "Block (of steel, gold, etc)" , "Mass of precious metal" , "Bar, brick of metal" .)