S-shaped moulding (4)
I believe the answer is:
ogee
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">s-shaped moulding</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ogee that I've seen before include "bit of Gothic architecture?" , "architectural feature" , "S-shaped line" , "S-shaped curve" , "S-shaped moulding" .)