noun. A polygon having four sides.

adjective. Having four sides.

Having four sides; composed of four lines.

noun. A figure formed of four Straight lines.

noun. Milit., the space inclosed between, and defended by, four fortresses: as, the Bulgarian quadrilateral. The most famous quadrilateral was that in northern Italy, inclosed by the fortresses of Peschiera, Mantua, Verona, and Legnago.

noun. A plane figure having four sides, and consequently four angles; a quadrangular figure; any figure formed by four lines.

noun. An area defended by four fortresses supporting each other.

noun. 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.

adjective. Having four sides, and consequently four angles; quadrangular.

noun. a polygon having four sides.

adjective. having four sides.

adjective. having four sides

noun. a four-sided polygon

"For instance, the term quadrilateral, or four-sided rectilinear figure, is correctly divided into square, oblong, rhombus, rhomboid and trapezium."

circumscriptible quadrilateral  cyclic quadrilateral  heronic cyclic  inscriptible quadrilateral  plane quadrilateral  

many-sided  multilateral  

control-panel  eidolon  face-centered  fifteen-foot  formidable-looking  

bifacial  bilateral  biquadratic  cube-shaped  cubed