Webster's Writer's Dictionary

AXLE

Ax"le [OE. axel, exel, shoulder, AS. ; akin to AS. eax axle, Sw. & Dan. axel shoulder, ~, G. achse axle, achsel shoulder, L. axis axle, Gr. aksha, L. axilla shoulder joint: cf. F. essieu, axle, OF. aissel, fr. dim. of L. axis. Axis.]

1. The pin or spindle on which a wheel revolves, or which revolves with a wheel.

2. A transverse bar or shaft connecting the opposite wheels of a car or carriage; an axletree.

3. An axis; as, the sun's axle. Had from her axle torn The steadfast earth. Milton.

Note: Railway axles are called leading and trailing from their position in the front or in the rear of a car or truck respectively.