rhombus

noun5

1. •
   A parallelogram having all sides of equal length.
2. •
   The rhombus diamond, as one of the suits seen in a deck of playing cards ( or ).
3. •
   In early Greek religion, an instrument whirled on the end of a string similar to a bullroarer.

   • The Greeks also used an instrument called a rhombus, or witches' wheel. As the wheel spun round, it was thought that influence was gained over certain people or circumstances. — 1936
4. •
   (no longer used) Any of several flatfishes, including the brill and turbot, once considered part of the genus Rhombus, now in Scophthalmus.

   • the greedy Tuberon or Shark arm'd with a double row of venemous teeth pursues them, directed by a little Rhombus, Musculus or pilot-fish that scuds to and fro to bring intelligence [...]. — 1638
5. •
   (no longer used) Snails, now in genus Conus or family Conidae.