Emily Dickinson Lexicon

AX'IS, n. [plur. Axes. L.; Gr. αξων, Russ. os, or osi; Sax. æx; Fr. axe, or aissieu; G. achse; D. as; It. asse; Sp. exe; Port. exo, eixo.]

1. The straight line, real or imaginary, passing through a body, on which it revolves, or may revolve; as the axis of the earth.
2. In geometry, a straight line in a plane figure, about which it revolves to produce a solid.
3. In conic sections, a right line dividing the section into two equal parts, and cutting all its ordinates at right angles.
4. In mechanics, the axis of a balance is that line about which it moves, or rather turns. The axis of oscillation is a right line parallel to the horizon passing through the center, about which a pendulum vibrates. The axis in peritrochio is a wheel concentric with the base of a cylinder, and movable with it about its axis.
5. In optics, a particular ray of light from any object which falls perpendicularly on the eye.
6. In architecture, spiral axis is the axis of a twisted column spirally drawn in order to trace the circumvolutions without. Axis of the Ionic capital is a line passing perpendicularly through the middle of the eye of the volute. The axis of a vessel is an imaginary line passing through the middle of it, perpendicular to its base, and equally distant from its sides.
7. In botany, axis is a taper column in the center of some flowers or catkins, about which the other parts are disposed. The stem or main body of a plant, with its root. It is formed by the development of an embryo or leaf-bud. – Lindley.
8. In anatomy, axis is the name of the second verteber of the neck; it has a tooth which enters into the first verteber, and this tooth is by some called the axis. – Encyc.