Passing through (3)
I believe the answer is:
via
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">passing through</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for via that I've seen before include "By means of" , "Going through" , "A Roman way" , "Roman road" , "Passing through" .)