Epididymis
Organs
The epididymis (plural: epididymides) is a tube that connects a testicle to a vas deferens in the male reproductive system.
It is present in all male reptiles, birds, and mammals.
It is a single, narrow, tightly-coiled tube in adult humans, 6 to 7 meters (20 to 23 ft) in length connecting the efferent ducts from the rear of each testicle to its vas deferens.
Definition from Wikipedia, CC BY-SA 4.0.