What does Boxing Day have to do with boxing?
1706, "a trapezium," from Modern Latin trapezoides, from Late Greek trapezoeides (Proclus), special use by Euclid of Greek trapezoeides "trapezium-shaped," from trapeza, literally "table" (see trapezium), + -oeides "shaped" (see -oid). Technically, a quadrilateral figure with no two sides parallel. But in English since c.1800, often confused with trapezium in its sense of "a quadrilateral figure having only two sides parallel."
trapezoid trap·e·zoid (trāp'ĭ-zoid')
A quadrilateral having two parallel sides.
A small bone in the wrist situated near the base of the index finger and articulating with the second metacarpal, trapezium, capitate, and scaphoid bones.
A four-sided polygon in which two sides are parallel and two are not.