parallelogram (n.)

"quadrilateral whose opposite sides are parallel," 1560s, from Middle French parallélogramme (1550s) and directly from Late Latin parallelogrammum, from Greek parallelogrammon noun use of a neuter adjective meaning "bounded by parallel lines," from parallelos (see parallel) + stem of graphein "to write" (see -graphy). Related: Parallelogrammic; parallelogramical.