Pack (down) (4)
I believe the answer is:
tamp
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pack down</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 tamp that I've seen before include "Pack (eg earth) down firmly" , "Pack down eg tobacco in a pipe" , "Press, pack (down)" , "Push down tobacco" , "press down firmly" .)