Tapering stone pillar (7)
I believe the answer is:
obelisk
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tapering stone pillar</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 obelisk that I've seen before include "Needle-like column" , "Tapering, rectangular stone column" , "Ancient Egyptian monument" , "Tapering square stone monument" , "Cleopatra's Needle, perhaps?" .)