Inch and Ounce Are the Same Latin Word
An inch is a twelfth of a foot. The Latin word meant a twelfth part of anything.
An inch is a unit of length equal to one twelfth of a foot. Latin *uncia* meant a twelfth part of anything, and English borrowed it twice: as *inch* for a twelfth of a foot and as *ounce* for a twelfth of the old Roman pound. Two units that seem to have nothing in common are the same word. The inch was fixed at exactly 25.4 millimetres by international agreement in 1959, defining it by reference to the metre.
- A twelfth of a foot. *Six inches.*
- A small amount. *Give an inch.*
- To move slowly. *Inched forward.*
- Ounce — the same root. *An ounce.*
- Latin — *uncia*, a twelfth. *The root.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | inch | An inch. |
| Plural | inches | Inches. |
| Verb | inch | Inching. |
| Related | ounce | An ounce. |
| Latin | uncia | A twelfth. |
- The board is three inches wide.Measure.
- The car inched forward.Movement.
- Inch and ounce share a root.Etymology.
Roman twelfths
- Uncia meant a twelfth part of any whole
- A twelfth of a foot became the inch
- A twelfth of a pound became the ounce
- Twelve divides evenly by 2, 3, 4 and 6
- That flexibility is why twelfths were preferred to tenths
Old English *ynce*, from Latin *uncia*, a twelfth part, the same source as *ounce*.
Are inch and ounce related?
Yes. Both come from Latin uncia, a twelfth. One was a twelfth of a foot, the other a twelfth of a Roman pound.
How long is an inch exactly?
Exactly 25.4 millimetres, fixed by international agreement in 1959.