Military installation
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">military installation</span>' is the definition.<br/ ><span class="explanation-format__explanation">(silo is a kind of military installation)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for silo that I've seen before include "Tower for storing grain" , "Storage unit for animal feed" , "Cylindrical storage tower" , "Farm store; soil (anag.)" , "Storage space for fodder" .)