Having four right angles.

Roget 97: quartered etc. v.; quadrifid^†, quadripartite.    rectangular.   

Roget 244: angular, bent, crooked, aduncous^†, uncinated^†, aquiline, jagged, serrated; falciform^†, falcated^†; furcated^†, forked, bifurcate, zigzag; furcular^†; hooked; dovetailed; knock kneed, crinkled, akimbo, kimbo^†, geniculated^†; oblique etc. 217.    fusiform [Micro.], wedge-shaped, cuneiform; cuneate^†, multangular^†, oxygonal^†; triangular, trigonal^†, trilateral; quadrangular, quadrilateral; foursquare; rectangular, square, multilateral; polygonal etc. n.; cubical, rhomboid, rhomboidal, pyramidal.    ... show more

Polish: prostokątny

Having a set of mutually perpendicular axes; meeting at right angles:
— A rectangular Cartesian coordinate system.

synonym: orthogonal.

Roget 216a: orthogonal, perpendicular; rectangular; uncorrelated.   

Roget 212: vertical, upright, erect, perpendicular, plumb, normal, straight, bolt, upright; rampant; standing up etc. v.; rectangular, orthogonal etc. 216.1. ... show more