Axis

In mathematics, an axis is a straight line around which a geometric figure can be rotated. An axis of symmetry is a line with respect to which a body can be symmetrical. The term is also applied for the axis of a graph; the horizontal axis x-axis, the vertical y-axis and the z-axis is a possible third axis used for three-dimensional graphing.

In anatomy, the axis is the second vertebra.

In history, Axis can also be used to denote an alliance or partnership. When talking about the Axis (capitalised), usually the alliance of Germany, Italy and Japan in World War II is meant (see Axis powers).

See also Axis (deer), cartesian coordinate system, ellipse, Axis of evil