axis Definition

axis
noun axes

1. An imaginary straight line around which an object, eg a planet, rotates.

Thesaurus: axle, pivot, spindle, longitude, centre line.
2. An imaginary straight line around which an object is symmetrical.
3. geom.
One of the lines of reference used to specify the position of points on a graph, eg the horizontal x-axis and vertical y-axis in Cartesian coordinates.
4. anatomy.
In vertebrates: the second cervical vertebra of the spine, which articulates with the atlas vertebra and enables the head to be moved from side to side.

Derivative: axial
adj

Derivative: axially
adverb

Derivative: axile
adj

Coinciding with an axis.

Etymology: 16c: from Latin axis axletree, the Earth's axis.