Meaning of choroid in English:


(also chorioid)
(also chorioid, choroid coat)

Pronunciation /ˈkɔːrɔɪd/ /ˈkɒrɔɪd/


  • Resembling the chorion, particularly in containing many blood vessels.

    ‘As can be seen in the left hemisphere, the choroid plexus protrudes into the central part of the lateral ventricle, and the route of entry of the plexus is via the choroid fissure, between the fornix and the lamina affixa.’
    • ‘Medaka P is strongly expressed in the eyeball of embryos and adults, where melanin is produced in the choroid membrane and retinal pigment epithelium.’
    • ‘Thus the choroid plexuses of the lateral ventricles are in fact only lateral expansions of the tela choroidea of the 3rd ventricle, and they extend into the lateral ventricles by way of the choroid fissures.’
    • ‘The choroid plexus of the 3rd ventricle is united with the choroid plexus of the lateral ventricle via the choroid fissure between thalamus and fornix.’
    • ‘Defects are observed inside the melanosomes distributed on the skin, peritoneum and choroid membrane, but melanosomes in the pigment epithelial cells are terminally differentiated.’


  • The pigmented vascular layer of the eyeball between the retina and the sclera.

    ‘Underneath the retina is the choroid - a thin layer of blood vessels that supplies oxygen and nutrients to the retina.’
    • ‘These changes occur in the optic disc or the place from where the optic nerve exits the eye, the retina or the light sensitive layer and the layer behind the retina called the choroid.’
    • ‘Choroidal melanoma is a tumor of the eye that forms from pigmented cells of the choroid, a layer of vascular tissue in the back of the eye.’
    • ‘In this condition, fluid accumulates under the retina because of a leaky blood vessel in the choroid, a layer of blood vessels located under the retina.’
    • ‘High myopia often leads to atrophy of the choroid and subsequent retinal macular degeneration, with loss of central visual acuity and high incidence of retinal detachment, glaucoma, and strabismus’


Mid 17th century from Greek khoroeidēs (adjective), alteration of khorioeidēs, from khorion (see chorion).