(Geometry)a four-sided plane figure, especially a square or rectangle (几何)四角形,四边形 ■a square or rectangular space or courtyard enclosed by buildings (由建筑物环绕的)四方场地,四方院
语源
late Middle English: from Old French, or from late Latin quadrangulum 'square', neuter of quadrangulus, from Latin 'four' + angulus 'corner, angle'