|—n , pl axes|
|1.||a real or imaginary line about which a body, such as an aircraft, can rotate or about which an object, form, composition, or geometrical construction is symmetrical|
|2.||one of two or three reference lines used in coordinate geometry to locate a point in a plane or in space|
|3.||anatomy Compare atlas the second cervical vertebra|
|4.||botany the main central part of a plant, typically consisting of the stem and root, from which secondary branches and other parts develop|
|5.||an alliance between a number of states to coordinate their foreign policy|
|6.||optics Also called: principal axis the line of symmetry of an optical system, such as the line passing through the centre of a lens|
|7.||geology an imaginary line along the crest of an anticline or the trough of a syncline|
|8.||crystallog one of three lines passing through the centre of a crystal and used to characterize its symmetry|
|[C14: from Latin: axletree, earth's axis; related to Greek axōn axis]|
axis ax·is (āk'sĭs)
n. pl. ax·es (āk'sēz')
A center line to which parts of a structure or body may be referred.
The second cervical vertebra. Also called epistropheus, vertebra dentata.
An artery that divides into many branches at its origin.
|axis (āk'sĭs) Pronunciation Key
Plural axes (āk'sēz')