Bullion bar (5)
I believe the answer is:
ingot
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bullion bar</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ingot that I've seen before include "Metallic bar" , "A lump of metal, perhaps gold" , "Piece of cast metal" , "Mass of cast metal" , "Block (of steel, gold, etc)" .)