Polyhedrons (8)
I believe the answer is:
pyramids
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">polyhedrons</span>' is the definition.<br/ ><span class="explanation-format__explanation">(pyramid is a kind of polyhedron)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for pyramids that I've seen before include "Giza monuments" , "Egyptian polyhedrons" , "Giza landmarks" , "Massive royal tombs of ancient Egypt" , "Monumental tombs of the Pharoahs" .)