Mold and Mould Are the Same Word Twice Over
Mold is a shaping form and also a fungus. British English spells both with a u.
Mold is a hollow form used for shaping material, and also a woolly fungus that grows on damp matter. The two are separate words that happen to look alike: the shaping form comes from Latin *modulus*, a small measure, while the fungus comes from a Norse word meaning mouldy. A third *mould*, meaning loose earth, survives in *leaf mould* and in *mouldboard*, the curved plate of a plough. American English spells all three without the u, following Noah Webster.
- A shaping form. *A jelly mold.*
- A fungus. *Bread mold.*
- Loose earth. *Leaf mould.*
- To shape. *Molding clay.*
- Latin — *modulus*. *The form sense.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | mold | A mold. |
| Verb | mold | Molding. |
| Adjective | moldy | Moldy. |
| British | mould | A mould. |
| Latin | modulus | A small measure. |
- Pour it into the mold.Form.
- The bread grew mold.Fungus.
- Leaf mould enriches soil.Earth.
Why American spelling dropped the u
- Noah Webster set out to simplify American spelling
- Colour, honour, favour lost their u
- Mould, smoulder, moult followed the same pattern
- Centre became center, defence became defense
- Not every proposal stuck — tung for tongue failed
The form is Old French *modle*, from Latin *modulus*. The fungus is from Old Norse *mygla*, to grow mouldy.
Are the two molds related?
No. The shaping form comes from Latin modulus, while the fungus comes from a Norse word meaning mouldy.
Why do Americans write mold and the British mould?
Noah Webster's spelling reforms dropped the u in a set of words, including colour, honour, mould and smoulder.