Gold bar (5)
I believe the answer is:
ingot
'gold bar' is the definition.
(I've seen this before)
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" .)