Cow part (5)
I believe the answer is:
udder
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cow part</span>' is the definition.<br/ ><span class="explanation-format__explanation">('udder' is part of 'cow')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for udder that I've seen before include "Animal mammary gland" , "Milk supply" , "Teat of a cow" , "Animal organ with more than one teat" , "Cow's teat" .)