Rhombus

A square is both a rectangle and a rhombus.

The rectangle and the rhombus are parallelograms.

A square is a rectangle and a rhombus at the same time.

A square is a rhombic rectangle or, if you prefer, a rectangular rhombus.

A rhombus and a rectangle are special parallelograms. All three of these are special quadrilaterals.

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.

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 [...].