Eyebrow shape
I believe the answer is:
arch
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">eyebrow shape</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 arch that I've seen before include "Shrewd; bridge" , "Knowing, sly" , "Bridge span" , "one under a foot?" , "which may fall and inconvenience walkers" .)