chorion

[ kawr-ee-on, kohr- ]

noun

1. Embryology. the outermost of the extraembryonic membranes of land vertebrates, contributing to the formation of the placenta in the placental mammals.
2. Zoology. the membrane around the eggs of certain insects, secreted by cells of the ovary.

chorion

/ ˈkɔːrɪən /

noun

1. See amnion
   the outer of two membranes that form a sac around the embryonic reptile, bird, or mammal: contributes to the placenta in mammals See also amnion

chorion

/ kôr′ē-ŏn′ /

1. The outer membrane that encloses the embryo of a reptile, bird, or mammal. In mammals, the chorion contributes to the development of the placenta.

Derived Forms

• ˌchoriˈonic, adjective

Other Words From

• chori·onic chori·al adjective
• subcho·ri·onic adjective

Word History and Origins

Origin of chorion¹

1535–45; < New Latin < Greek chórion membrane enclosing the fetus

Word History and Origins

Origin of chorion¹

C16: from Greek khorion afterbirth

Example Sentences

The first thing that is formed is the amnios; the next the chorion; and they enwrap the seed round like a curtain.

From Project Gutenberg

The whole being surrounded by two membranous coverings, the outer one called the chorion, and the inner one the amnion.

From Project Gutenberg

Twins coming from one egg have the same chorion and can thereby be diagnosed as such.

From Project Gutenberg

It also sometimes brings away part of the amnios, and even the chorion, upon its head like a cap.

From Project Gutenberg

The surface of the chorion is covered evenly with minute villi, constituting a diffuse non-deciduate placenta.

From Project Gutenberg