- Geometry.
- (in Euclidean geometry) any rectilinear quadrilateral plane figure not a parallelogram.
- a quadrilateral plane figure of which no two sides are parallel.
- trapezoid (def. 1a).
- a bone in the wrist that articulates with the metacarpal bone of the thumb.
- a quadrilateral having two parallel sides of unequal length
- a quadrilateral having neither pair of sides parallel
- a small bone of the wrist near the base of the thumb
