rhombus

Short definition from Wiktionary

Noun

1. 1
   A parallelogram having all sides of equal length.
2. 2
   A parallelogram having all sides of equal length: The rhombus diamond, as one of the suits seen in a deck of playing cards ( or ).
3. 3
   In early Greek religion, an instrument whirled on the end of a string similar to a bullroarer.
4. 4
   Any of several flatfishes, including the brill and turbot, once considered part of the genus Rhombus, now in Scophthalmus.
5. 5
   Snails, now in genus Conus or family Conidae.