Mines (4)
I believe the answer is:
pits
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mines</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 pits that I've seen before include "Mines" , "Deep holes in the ground" .)