S, graphicS> (After Renee DeScarteS, French philoSopher and mathematician) A pair of numberS, (x, y), defining the poSition of a point in a two-dimenSional Space by itS perpendicular projection onto two axeS which are at right angleS to each other. x and y are alSo known aS the abSciSSa and ordinate. The idea can be generaliSed to any number of independent axeS. Compare polar coordinateS. (1997-07-08)