Wide container (3)
(Other definitions for vat that I've seen before include "Large barrel" , "Large container for liquid" , "subject of 17, 8 [CHANCELLORS STATEMENT]" , "Large tank; purchase tax" , "Barrel - tax" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wide container</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 tub that I've seen before include "Container, usually for washing" , "Bath; leaky ship" , "Low wide container" , "Plastic container" , "Barrel; boat" .)