(ak′sis) noun plural ax·es (ak′sēz)
1. A line around which a turning body revolves or may be supposed to revolve.
2. Geom. a One of the principal lines through the center of a plane or solid figure, especially the longest or shortest, or a line as to which the plane figure or solid is symmetrical, b A fixed line along which distances are measured or to which positions are referred.
3. An imaginary line through the center of a drawing or sculpture for purposes of measurement or reference.
4. The central line about which parts of a body are symmetrically arranged.
5. Bot. The central body, part, line, or longitudinal support on, along, or above which organs or other parts are arranged.
6. Anat. a A short arterial trunk from which several nearly equal branches radiate, b The second cervical vertebra, or the large, blunt, toothlike odontoid process which surmounts it and forms a pivot on which the atlas and head turn.
7. One of the lines of reference meeting at the center of a crystal, and determining to which system it belongs.
8. Geol. The dominant central section of a mountain chain, or the line tracing the crest throughout its length.
9. Aeron. One of the three axes of an aircraft.
10. An affiliation or coalition of two or more nations to promote and insure mutual interest, cooperation, and solidarity of front in their relations with foreign powers; also, the nations so affiliated. [<L, axis, axle]

(ak′sis) noun
A small deer (genus Axis) of southern Asia, having the body spotted with white. Also axis deer. [<L]