A rhombus is a parallelogram with four equal sides, like a square. Unlike a square, however, a rhombus has opposite and equal acute angles, and opposite equal obtuse angles — creating a diamond shape. It’s like a square that's leaning.

The rhombus gets its name from the Greek rhómbos, which means "a spinning top." This word comes from the shape of an object that was tied to a cord and spun around, making a great noise. This "bullroarer" was used to taunt bulls into action during bull-fighting events. This rhombus-shaped object has been documented as being used for religious rites and games all over the ancient world. Nowadays, we prefer to study the rhombus shape in geometry.

Definitions of rhombus

n a parallelogram with four equal sides; an oblique-angled equilateral parallelogram

diamond, rhomb
Type of:
a quadrilateral whose opposite sides are both parallel and equal in length