Military body (5)
I believe the answer is:
corps
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">military body</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for corps that I've seen before include "Branch of an army" , "ballet group" , "army band" , "Specialised mil. body" , "Large army group" .)