Etymology

Recorded since 1570, from Late Latin trapezium, from trapezion (trapezion) "irregular quadrilateral," literally "a little table", diminutive of trapeza "table", itself from tra- "four" + peza "foot, edge"

Noun

1. A four-sided polygon with two sides parallel; a trapezoid (modern sense)
2. A four-sided polygon with no parallel sides and no sides equal; a simple convex irregular quadrilateral.
3. A bone of the carpus at the base of the first metacarpal, or thumb.
4. 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.

Usage notes

The terms and have partially swapped meanings in the US and Canada as compared with the rest of the world.

Synonyms

trapezoid irregular quadrilateral.