ordinate

In mathematics, ordinate most often refers to that element of an ordered pair which is plotted on the vertical axis of a two-dimensional Cartesian coordinate system, as opposed to the abscissa. The term can also refer to the vertical axis (typically y-axis) of a two-dimensional graph (because that axis is used to define and measure the vertical coordinates of points in the space). An ordered pair consists of two terms—the abscissa (horizontal, usually x) and the ordinate (vertical, usually y)—which define the location of a point in two-dimensional rectangular space.