choroid

noun

cho·​roid ˈkȯr-ˌȯid How to pronounce choroid (audio)
variants or less commonly chorioid
: a vascular membrane containing large branched pigmented cells that lies between the retina and the sclera of the vertebrate eye

called also choroid coat

see eye illustration
choroid adjective
or choroidal

Examples of choroid in a Sentence

Recent Examples on the Web The injury caused a rupture to his left choroid, which is the part of the eye located between the sclera, or whites of the eye, and the retina, the layer of cells lining the internal wall at the back of the eye, according to the American Academy of Ophthalmology. Nikki Dobrin, Peoplemag, 1 Sep. 2023 In the choroid plexus, a tissue in the large cavities of the brain that produces cerebrospinal fluid (CSF), the walls of blood vessels are much leakier. Yasemin Saplakoglu, Quanta Magazine, 20 June 2023 Alpha-klotho is highly abundant in a central structure of the brain called the choroid plexus. William A. Haseltine, Forbes, 20 Feb. 2023 The team also discovered that one of the astronauts developed folds in the choroid, the layer of blood vessels and tissue between the retina and the sclera. Jennifer Leman, Popular Mechanics, 3 Mar. 2022 The condition, known technically as birdshot chorioretinopathy, causes severe, progressive inflammation of the retina and the choroid, the vascular layer of the eye. Caren Chesler, Popular Mechanics, 6 Mar. 2019 Nightstar, a gene therapy company based in the U.K., has been undergoing clinical trials to address choroideremia, a mutation in the CHM gene that leads to degeneration of the choroid (Misrok’s vision is affected by choroid damage). Caren Chesler, Popular Mechanics, 6 Mar. 2019 Behind the retina is a part of the eye called the choroid. sandiegouniontribune.com, 20 Sep. 2017

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'choroid.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

New Latin choroides resembling the chorion, from Greek chorioeidēs, from chorion chorion

First Known Use

1683, in the meaning defined above

Time Traveler
The first known use of choroid was in 1683

Dictionary Entries Near choroid

Cite this Entry

“Choroid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/choroid. Accessed 15 Apr. 2024.

Kids Definition

choroid

noun
cho·​roid ˈkōr-ˌȯid How to pronounce choroid (audio)
ˈkȯr-
variants also chorioid
: the middle layer of the eye of vertebrates that contains pigment and is located between the sclera and the retina
choroid adjective

Medical Definition

choroid

noun
variants also chorioid
: a vascular membrane containing large branched pigment cells that lies between the retina and the sclera of the eye

called also choroid coat

choroid adjective
or choroidal

More from Merriam-Webster on choroid

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