/ˌepiˈdidəməs/
Noun, pl. epididymides
1. A narrow, tightly-coiled tube connecting the efferent ducts from the rear of each testicle to its vas deferens, where sperm are stored during maturation. (wiktionary.org)
2. Part of the male reproductive system and is present in all male amniotes. It is a single, narrow, tightly-coiled tube (in adult humans, six to seven meters in length) connecting the efferent ducts from the rear of each testicle to its vas deferens. (wikipedia.org)
3. A highly convoluted duct behind the testis, along which sperm passes to the vas deferens. (Google Dictionary)
4. An elongated cordlike structure along the posterior border of the testis; its coiled duct provides for storage, transit, and maturation of spermatozoa and is continuous with the ductus deferens. (Dorland’s Medical Dictionary for Health Consumers)
Word origin: From Ancient Greek ἐπιδιδυμίς (epididymís), from ἐπί (epi, “upon, over”) + δίδυμος (didumos, “testicle”).