. 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. |

| x-ax·is (ěks'āk'sĭs) n. pl. x-ax·es (-āk'sēz)
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x-axis (ěks'āk'sĭs) Pronunciation Key
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