Something curved in shape (3)
I believe the answer is:
arc
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">something curved in shape</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for arc that I've seen before include "development of plot" , "Half-moon" , "Curved path" , "Section of circumference" , "Luminous electrical discharge" .)