Single part (4)

I believe the answer is:
unit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">single part</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for unit that I've seen before include "Single person - group of people" , "Subdivision of a military group" , "Single element; one" , "Kitchen element?" , "Single complete domestic fixture" .)