A Grammatical Dictionary of Botanical Latin

Parallelogrammon,-i (s.n.II), abl. sg. parallelogrammo, nom. & acc. pl. parallelogramma: is a simple (non self-intersecting) quadrilateral with two pairs of parallel sides: the opposite or facing sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure; bounded by parallel lines; a quadrilateral with opposite sides parallel = quadrangle, q.v. [> L. gramma,-ae (s.f.I), from Gk. grammE (Lewis & Short), a line in writing, a stroke of the pen];

Quadrilateral, “a plane figure of four sides and consequently four angles; a quadrangular figure; a plane figure formed by four lines” (WIII) = quadrangle.

Quadrangle, “a plane figure having four angles and consequently four sides; any figure having four angles” (WIII) = quadrilateral: quadriangulum,-i (s.n.II), abl. sg. quadriangulo; also quadrangulum,-i (s.n.II), abl. sg. quadrangulo.

Figura,-ae (s.f.I) quadrilateralis.

Parallelogram: “a quadrilateral with opposite sides parallel (see rectangle, rhomboid, rhombus)(WIII)

Rectangle – a parallelogram with four angles of equal size: rectangulum,-i (s.n.II), q.v., abl.sg. rectangulo.

Rhombus – a parallelogram with four sides of equal length: rhombus,-i (s.m.II),q.v., abl. sg. rhombo.

Square – a parallelogram with four sides of equal length and angles of equal size (= right angles): quadratum,-i (s.n.II), q.v., abl. sg. quadrato; quadrum,-i (s.n.II), abl. sg. quadro.

NOTE: a rhomboid: a quadrilateral whose opposite sides are parallel and adjacent sides are unequal, and whose angles are not right angled: rhomboides,-is (s.n.II), abl. sg. rhomboide = Gk. r[h]omboeides, in mathematics “a four-sided figure, whose opposite sides and angles are equal, a rhomboid” (Lewis & Short)