Milk supplier (5)
I believe the answer is:
dairy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">milk supplier</span>' is the definition.<br/ ><span class="explanation-format__explanation">(building which processes cow's milk)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dairy that I've seen before include "Where butter's made" , "Place for storing milk products" , "milk supplier" , "Milk products collectively" , "Factory for milk products" .)