(algebraic geometry) The axis on a graph that is usually drawn from bottom to top and usually shows the range of values of variable dependent on one other variable, or the second of two independent variables.

(mathematics) The line containing the locus of points from which the segments respectively tangent to two given circles have equal length.

plural of Axis power

The axis about which any body rotates. / The line joining the North Pole and South Pole about which the Earth rotates daily.

(mathematics) The vertical line in the complex plane, every point on which corresponds to a complex number having zero real component

(mathematics) The horizontal line in the complex plane, every point on which corresponds to a real number

(geometry) Any of one or more lines about which a geometric figure is symmetric

(optics) An imaginary line within an optical system around which there is rotational symmetry.

(mathematics, geometry) One of the lines in the coordinate system that represents one of the dimensions.

The optical axis of an eye (extending from the viewed object through the centre of the pupil to the yellow spot of the retina)