Very busy place (4)
I believe the answer is:
hive
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">very busy place</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for hive that I've seen before include "home of queen" , "A box for bees" , "Where to get honey" , "Bee colony" , "Scene of activity" .)