Underside (6)
I believe the answer is:
bottom
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">underside</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that underside can be written as bottom)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for bottom that I've seen before include "Lowest part or underside" , "Shakespeare's weaver" , "Crack" , "dry bed" , "seat" .)