In a group (2,5)
I believe the answer is:
en masse
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">in a group</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 en masse that I've seen before include "Many as one" , "All together (Fr.)" , "All together - in France (2.5)" , "In force" , "in concert" .)