What a drover drives
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">what a drover drives</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 herd that I've seen before include "Collection of swine" , "Group of people behaving like sheep?" , "Group of cows, elephants etc" , "pack" , "Drove" .)