Spelling.School · How to spell

How to spell diameter

What it means: The length across a circle through its center.

In a sentence: The diameter of the cookie is bigger than my hand! ▶

The part people get wrong

Watch for an unstressed vowel that is hard to hear. Often misspelled as diamenter or diametre.

Same family: metric, millimeter, centimeter, perimeter, geometry. If you can spell one, the shared part carries to the others.

Where it comes from: “Diameter” comes from the Greek word “diametros,” which literally means “measure across.” It is built from “dia-” meaning “across” and “metron” meaning “measure.”

Patterns it uses: The unstressed vowel (schwa)

Try spelling it

You will hear the word and a sentence. Type it and press Enter. Then four more words from the same level, so you know where you stand.

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