Axle and Axis Are the Same Word Twice
An axle is a rod on which wheels turn. It and axis descend from one ancient root through different languages.
An axle is a rod passing through the centre of a wheel, on which the wheel turns. *Axle* and *axis* are effectively the same word arriving twice: axle came through Old Norse and Old English, axis directly from Latin. Both descend from an ancient Indo-European root that also gives Greek *axon*, the source of *axon*, the long fibre of a nerve cell. The wheel and axle together form one of the six classical simple machines.
- A wheel rod. *A rear axle.*
- Axis — the Latin form. *An axis.*
- Axon — a nerve fibre. *An axon.*
- Wheel and axle — a simple machine. *A simple machine.*
- Old Norse — *öxull*. *The source.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | axle | An axle. |
| Plural | axles | Axles. |
| Related | axis | An axis. |
| Related | axon | An axon. |
| Norse | öxull | An axle. |
- The rear axle needed replacing.Vehicle.
- Axle and axis share a root.Etymology.
- An axon carries nerve signals.Biology.
How a wheel and axle multiplies force
- The wheel's rim travels much further than the axle surface
- A small force at the rim becomes a large force at the axle
- A doorknob works this way, as does a screwdriver handle
- Steering wheels and winches use the same principle
- It is really a lever rotating continuously
Old Norse *öxull* and Old English *eaxl*, from an Indo-European root shared with Latin *axis*.
Are axle and axis related?
Yes. They descend from the same ancient root, axle through Germanic and axis directly from Latin.
Is a nerve axon related?
Yes. It comes from Greek axon, the same root, named because it runs like an axis through the cell.