What is the meaning of Trapezium?

A quadrilateral with two sides parallel.

A quadrilateral with two sides parallel and two sides non-parallel.

A four-sided polygon with no parallel sides and no sides equal; a simple convex irregular quadrilateral.

The trapezium bone of the wrist.

A region on the ventral side of the brain, either just back of the pons Varolii, or, as in man, covered by the posterior extension of its transverse fibers.

trapezium, trapezoid (four-sided shape with no sides parallel and no equal sides)

trapezium, trapezoid (four-sided shape with no sides parallel and no equal sides)

Source: wiktionary.org