QUADRILATERALS
Noun
quadrilaterals
plural of quadrilateral
Source: Wiktionary
QUADRILATERAL
Quad`ri*lat"er*al, a. Etym: [L. quadrilaterus: cf. F. quadrilatère,
quadrilatéral. See Quadri- and Lateral.]
Definition: Having four sides, and consequently four angles; quadrangular.
Quad`ri*lat"er*al, n.
1. (Geom.)
Definition: A plane figure having four sides, and consequently four angles;
a quadrangular figure; any figure formed by four lines.
2. An area defended by four fortresses supporting each other; as, the
Venetian quadrilateral, comprising Mantua, Peschiera, Verona, and
Legnano. Complete quadrilateral (Geom.), the figure made up of the
six straight lines that can be drawn through four points, A., B, C,
I, the lines being supposed to be produced indefinitely.
Source: Webster’s Unabridged Dictionary 1913 Edition