Occupy all of (4)
I believe the answer is:
fill
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">occupy all of</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 fill that I've seen before include "Top up" , "Become satiated" , "Occupy the whole of" , "Plug (a gap)" , "Block up (a hole, etc)" .)