Pār'al-lĕl'o-grām, n.

n. [Fr. parallélogramme, Sp. paralelogramo, It. parallelogrammo, Gr. παραλληλόγραμμον, fr. παράλληλος, parallel, and γραμμή, a stroke in writing, a line, from γράφειν, to write.] (Geom.) 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.

Parallelogram of forces, a parallelogram, the diagonal of which represents the resultant of two forces both in intensity and direction, when the forces themselves are represented in intensity and direction by the two sides of the parallelogram.