Jack-in-the-box part (3)
I believe the answer is:
lid
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">jack-in-the-box part</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for lid that I've seen before include "Cover for box or eye" , "Movable cover" , "Cap or top for container" , "Pie crust; cover" , "Top for pot or jar" .)