Bar of gold (5)
I believe the answer is:
ingot
'bar of gold' 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 precious metal" , "Seize quickly; steal" , "E.g. a gold bar" , "Unwrought metal cast in a mould" , "Piece of cast metal" .)