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a combining form meaning “nine,” used in the formation of compound words: enneahedron.
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Origin of ennea-

<Greek, combining form of ennéanine
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does ennea- mean?

Ennea- is a combining form used like a prefix meaning “nine.” It is used in some scientific and other technical terms.

Ennea- comes from the Greek ennéa, meaning “nine.” The Latin counterpart is nōnus, meaning “ninth” and source of the combining form nona-, which you can learn more about in our Words That Use articles for that form.

Examples of ennea-

An enneagon is “a polygon having nine angles and nine sides.” It’s also known as a nonagon.

The first part of the word, ennea-, means “nine.” The -gon portion of the word may also look familiar: it is a combining form meaning “angled” or “angular,” from the Greek gōnía. Enneagon literally translates to “nine-angled.”

Enneagon comes from the Greek enneágōnos, which features the equivalent form of ennea- in the language.

Another word you may have encountered that features ennea- is the Enneagram, a popular psychological model that categorizes human personality into nine types.

What are some words that use or are related to the combining form ennea-?

What are some other forms that ennea- may be commonly confused with?

Break it down!

The combining form -hedron means “face,” in the sense of a face of a geometrical solid figure, i.e., a cube has six faces. How many faces does an enneahedron have?

How to use ennea- in a sentence