Block of metal (5)
I believe the answer is:
ingot
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">block of metal</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ingot that I've seen before include "Mass of unwrought gold, for instance" , "Moulded metal bar" , "Mass of metal, especially gold or silver" , "Cast metal brick" , "Block of, eg, gold" .)