Extend over (4)
I believe the answer is:
span
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">extend over</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 span that I've seen before include "Bridge - spick and ___" , "Bridge or range" , "Interval; pair of yoked oxen" , "Extent - 9 inches" , "Extend from end to end, say bridge" .)