Be in front (4)
I believe the answer is:
lead
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">be in front</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for lead that I've seen before include "Go in front with heavy metal" , "Be in charge of, element" , "Metal - wire" , "Church windows include this" , "Heavy malleable metallic element" .)