A South Asian deer, the chital, Axis axis

(biology, dated) An axon.

plural of axis cylinder

(chiefly in the plural) A country in the alliance (in effect before and during World War II) of Nazi Germany, fascist Italy, imperial Japan, and a few other countries, which opposed the Allies.

The symmetrical axis of a body. In the case of the Earth, it differs from the rotational axis by a few meters, and so is a partial cause of the Earth's wobble.

The spin axis of a freely rotating body. In the case of the Earth, it differs from the figure axis by a few meters. This difference being a partial cause of the Earth's wobble.

The optical axis. / (crystallography, mineralogy) The direction in which a ray of light passing through a crystal does not suffer double refraction.

(anatomy) Synonym of cerebrospinal axis

The brain and the spinal cord

(geometry) Either of two axes in a conic section, such that each is parallel to the tangent at the extremity of the other.