parallelogram

A four-sided plane figure with opposite sides parallel.

In geometry, a quadrilateral whose opposite sides are parallel.

A pantograph.

A right-lined quadrilateral figure, whose opposite sides are parallel, and consequently equal; — sometimes restricted in popular usage to a rectangle, or quadrilateral figure which is longer than it is broad, and with right angles.

a parallelogram the diagonal of which represents the resultant of two velocities, forces, accelerations, momenta, etc., both in quantity and direction, when the velocities, forces, accelerations, momenta, etc., are represented in quantity and direction by the two adjacent sides of the parallelogram.

A convex quadrilateral in which each pair of opposite edges are parallel and of equal length.

a quadrilateral whose opposite sides are both parallel and equal in length