Mould Names a Shape, a Fungus and Loose Soil
A mould shapes material, and mould also names a fungus. British English spells all three with a u; American English does not.
A mould is a hollow form for shaping material, a fungus growing on damp surfaces, or loose earth. These are three separate words that converged: the shaping form is from Latin *modulus*, a measure; the fungus is from a Norse word meaning mouldy; and the soil sense is Old English *molde*, related to *mud*. American English spells all three *mold*. *Leaf mould* uses the soil sense, and *breaking the mould* uses the shaping one.
- A shaping form. *A jelly mould.*
- A fungus. *Mould on the bread.*
- Loose earth. *Leaf mould.*
- Mold — the American spelling. *Mold.*
- Break the mould — do something new. *Broke the mould.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun (UK) | mould | A mould. |
| Noun (US) | mold | A mold. |
| Verb | mould | Mould the clay. |
| Adjective | mouldy | Mouldy cheese. |
| Latin | modulus | A measure. |
- Pour the mixture into the mould.Shaping.
- There is mould on the wall.Fungus.
- Leaf mould improves the soil.Earth.
Three moulds, three origins
- The form — Latin *modulus*, a measure, through French
- The fungus — Old Norse *mygla*, mouldiness
- The soil — Old English *molde*, earth, related to *mud*
- Mouldboard — the curved plate of a plough, from the soil sense
- American spelling collapses all three into mold
The shaping sense is from Old French *modle*, from Latin *modulus*. The fungus and soil senses are separate Germanic words.
Are the moulds all the same word?
No. Three separate words converged in spelling: a shaping form from Latin, a fungus from Norse, and soil from Old English.
What does breaking the mould mean?
Doing something in a genuinely new way. The image is of destroying the form so no identical copy can be made.