Type of parallelogram
I believe the answer is:
rhomb
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">type of parallelogram</span>' is the definition.<br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for rhomb that I've seen before include "Equilateral parallelogram" , "Crystal shape" , "Crystal with six faces having parallel edges" , "Quadrilateral with four equal sides" , "Figure on plane" .)