Wingtip-to-wingtip measure
I believe the answer is:
span
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wingtip-to-wingtip measure</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 span that I've seen before include "Bridge or range" , "Measurement between tips of thumb, little finger" , "Stretch < fresh" , "Ox team; bridge" , "Pair of horses" .)