choroid choroid /ˈkɔːrəɪd/

noun

1. A highly vascular membrane in the eye between the retina and the sclera; a dark pigmentation minimizes the scattering of light inside the eye  ( choroid , choroid coat )
   a highly vascular membrane in the eye between the retina and the sclera; a dark pigmentation minimizes the scattering of light inside the eye