axi-, axl- +

(Latin: axle; chariot, wagon)

axial
Relating to, or operating, along an axis.
axial flow
Any flow parallel to an axis; especially, a flow in turbomachinery in which the flowing fluid always moves parallel to the length of the rotating shaft; as in an axial-flow turbine.
axial-flow turbine (s) (noun), axial-flow turbines (pl)
A common type of turbine with axial flow through the runner blades axially to the turbine shaft.
axis (s), axes (pl)
1. The uppermost cervical vertebra (called the atlas) which rotates around the odontoid process.

The joint between the axis and atlas is a pivot type of joint. It allows the head to turn.

2. A line around which a revolving body turns or around which a structure would turn if it did revolve.
3. A line around which specified parts of the body are arranged.

The Latin word axis means axle or pole. The axis bone serves as the axle about which the atlas (and the head) turn.

4. A straight line around which a body or geometric object rotates or may be conceived to rotate.
5. In mathematics, an unlimited line, half-line, or line segment serving to orient a space or a geometric object; especially, a line around which the object is symmetric.
6. A reference line from which distances or angles are measured in a coordinate system.
7. A center line to which parts of a structure or body may be referred.
8. In botany, the main stem or central part around which organs or plant parts; such as, branches are arranged.
9. One of three mutually perpendicular lines that define the orientation of an aircraft, with one being along its direction of travel and the other two being perpendicular to the direction of travel.
10. A line through the optical center of a lens that is perpendicular to both its surfaces.
11. An alliance of powers; such as, nations, to promote mutual interests and policies.

Axis The alliance of Germany and Italy in 1936, later including Japan and other nations, that opposed the Allies in World War II.

axle
1. A shaft on which a wheel or set of wheels revolves, especially a shaft under the body of a vehicle that connects a pair of wheels.
2. A supporting member, beam, or shaft designed to carry a wheel that may be attached to it, driven by it, or freely mounted on it.
3. The spindle on which one or more wheels revolve.
axle ratio
The ratio of the rotational speed of the drive shaft to the rotational speed of the drive wheels in an automotive vehicle.
axled
Having an axle.