chorion

[kawr-ee-on, kohr-]

noun

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

Origin of chorion

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

Related formscho·ri·on·ic, cho·ri·al, adjectivesub·cho·ri·on·ic, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for chorion

Historical Examples of chorion

The chorion is often ornamented with various processes, etc.
The Works of Francis Maitland Balfour, Volume II (of 4)
Francis Maitland Balfour
The chorion is an outward skin which compasseth the child in the womb.
The Works of Aristotle the Famous Philosopher
Anonymous
In the Cheiroptera (Vespertilio and Pteropus), the yolk-sack is large, and coalesces with part of the chorion.
The Works of Francis Maitland Balfour, Volume III (of 4)
Francis Maitland Balfour
The allantoic cavity persists (Owen), but the allantois only covers the placental area of the chorion.
The Works of Francis Maitland Balfour, Volume III (of 4)
Francis Maitland Balfour
This form of placenta occupies a broad zone of the chorion, leaving the two poles free.
The Works of Francis Maitland Balfour, Volume III (of 4)
Francis Maitland Balfour

British Dictionary definitions for chorion

chorion

noun

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

Derived Formschorionic or chorial, adjective

Word Origin for chorion

C16: from Greek khorion afterbirth

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for chorion

"outer membrane of the fetus," 1540s, medical Latin, from Greek khorion "membrane enclosing the fetus, afterbirth," perhaps from PIE *ghere- "gut, entrail" (see yarn).

chorion in Medicine

chorion

[kôr′ē-ŏn′]

The outer membrane enclosing the embryo in reptiles, birds, and mammals. In placental mammals it contributes to the development of the placenta.

Related formscho′ri•on′ic (-ŏn′ĭk) adj.

chorion in Science

chorion

[kôr′ē-ŏn′]

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