/əˈpendəmə/
Noun, pl. epyendymas
1. The thin epithelial membrane lining the ventricular system of the brain and the spinal cord. Ependyma is one of the four types of neuroglia in the central nervous system. It is involved in the production of cerebrospinal fluid (CSF). (wikipedia.org)
2. The thin membrane of glial cells lining the ventricles of the brain and the central canal of the spinal cord. (Google Dictionary)
3. Thin epithelial membrane lining the ventricles of the brain and the spinal cord canal. (wordnetweb.princeton.edu)
Word origin: From Ancient Greek ἐπένδυμα (ependuma), from ἐπενδύειν (ependuein), from ἐπί (epi, “over”) + ἐν (en, “on”) + δύειν (duein, “to put”).