Many-sided figure (7)
I believe the answer is:
polygon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">many-sided figure</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 polygon that I've seen before include "Closed plane figure with three or more straight sides" , "Geometric figure with five or more sides" , "Many-sided plane figure" , "Figure with many sides" , "Closed plane figure bounded by straight sides" .)