chorion

noun

cho·​ri·​on ˈkȯr-ē-ˌän How to pronounce chorion (audio)
: the highly vascular outer embryonic membrane of reptiles, birds, and mammals that in placental mammals is associated with the allantois in the formation of the placenta

Examples of chorion in a Sentence

Recent Examples on the Web
These examples are automatically compiled from online sources to illustrate current usage. Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
If the split is delayed, usually a week or so after conception, the processes of growing a placenta, chorion, and amniotic sac are already underway. Pamela Prindle Fierro, Parents, 30 July 2024 This is essentially a blood clot that can occur when the outermost membrane surrounding the embryo (the chorion) separates a little from the uterine wall, allowing some blood to pool in that space between the two. Amy Marturana, SELF, 28 Dec. 2018

Word History

Etymology

New Latin, from Greek, afterbirth

First Known Use

1545, in the meaning defined above

Time Traveler
The first known use of chorion was in 1545

Dictionary Entries Near chorion

Cite this Entry

“Chorion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/chorion. Accessed 18 Nov. 2024.

Kids Definition

chorion

noun
cho·​ri·​on ˈkōr-ē-ˌän How to pronounce chorion (audio)
ˈkȯr-
: the outer membrane that surrounds the embryo of reptiles, birds, and mammals and that in mammals with a placenta contributes to the formation of the placenta
chorionic
ˌkōr-ē-ˈän-ik
ˌkȯr-
adjective

Medical Definition

chorion

noun
cho·​ri·​on ˈkōr-ē-ˌän, ˈkȯr- How to pronounce chorion (audio)
: the highly vascular outer embryonic membrane that is associated with the allantois in the formation of the placenta

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