Pack tightly (4)
I believe the answer is:
cram
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pack tightly</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 cram that I've seen before include "Revise hard" , "prepare for exam" , "Study intensively" , "Pack in or study hard" , "Press together" .)