x-axis x-axis x-axis

noun, plural x-ax·es [eks-ak-seez] /ˈɛksˌæk siz/. Mathematics.

1. Also called axis of abscissas. (in a plane Cartesian coordinate system) the axis, usually horizontal, along which the abscissa is measured and from which the ordinate is measured.
2. (in a three-dimensional Cartesian coordinate system) the axis along which values of x are measured and at which both y and z equal zero.