Quiet period (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">quiet period</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 lull that I've seen before include "Calm - calm by deception" , "A temporary pause as in storm" , "Period of inactivity" , "Cessation of activity (before a storm?)" , "A temporary period of quiet, as in storm" .)