Put underground (5)
I believe the answer is:
inter
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">put underground</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 inter that I've seen before include "Cover" , "Lay to rest" , "top Italian side" , "Set deep" , "somewhere between ..." .)