a straight line about which a body or a geometric figure rotates or may be supposed to rotate
a straight line with respect to which a body or figure is symmetrical
any of the reference lines of a coordinate system
the second vertebra of the neck on which the head and first vertebra pivot
any of various parts that are central or fundamental or that lie on or constitute an axis
any of several imaginary reference lines used in describing a crystal structure
a partnership or alliance, e.g. the one between Germany and Italy in World War II
a plant stem
[Latin axis axle]