Measure the depth of (5)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">measure the depth of</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for plumb that I've seen before include "Utterly" , "Test alignment" , "Absolutely straight - sound" , "Lead weight; exactly" , "True" .)
(Other definitions for sound that I've seen before include "strait" , "Measure depth" , "well" , "Valid" , "Health - noise" .)