chorio-

1. a combining form meaning “chorion,” “choroid,” used in the formation of compound words:

   chorioallantois.

Word History and Origins

Origin of chorio-¹

Combining form representing Greek chórion

Words That Use chorio-

What does chorio- mean?

Chorio- is a combining form used like a prefix meaning either “chorion” or “choroid.” It is often used in scientific terms, especially in anatomy and biology.

The chorion is the outermost membrane surrounding the embryo of a reptile, bird, or a mammal, and which contributes to the formation of the placenta in mammals, including humans. Choroid means “like the chorion,” but it can also refer to the choroid coat, the vascular layer of the eye.

Chorio- comes from the Greek chórion, meaning “the outer membrane of the fetus.”

What are variants of chorio-?

When combined with words or word elements that begin with a vowel, chorio- becomes chori-, as in chorioma.

Related to chorio- are the combining forms choroido- and chorioido-, specifically used to represent the choroid coat.

Examples of chorio-

One example of a medical term that features chorio– is choriocarcinoma, also known as chorioma, meaning “any benign or malignant tumor of chorionic tissue.”

Here, chorio- means “chorion,” as in the embryo membrane. The second half of the word, carcinoma, means “tumor, cancer.” All together, choriocarcinoma literally translates to “chorion tumor.”

What are some words that use the combining form chorio-?

• chorioangioma
• chorioadenoma
• choriocapillaris
• chorioepithelioma
• chorioretinitis
• choriomeningitis
• chorioretinal

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

• cheiro-
• choreo-
• chromo-

Break it down!

The combining form -itis is used to denote a disease, particularly inflammation. With this in mind, what parts of the eye are inflamed from chorioretinitis?