Epididymis

[ep-i-did-uh-mis] /ˌɛp ɪˈdɪd ə mɪs/

noun, plural epididymides
[ep-i-di-dim-i-deez, -did-uh-mi-] /ˌɛp ɪ dɪˈdɪm ɪˌdiz, -ˈdɪd ə mɪ-/ (Show IPA). Anatomy.
1.
an elongated organ on the posterior surface of a testis that stores sperm while they mature and constitutes the convoluted beginning of the .
/ˌɛpɪˈdɪdɪmɪs/
noun (pl) -didymides (-dɪˈdɪmɪˌdiːz)
1.
(anatomy) a convoluted tube situated along the posterior margin of each testis, in which spermatozoa are stored and conveyed to the vas deferens
n.

c.1600, “fleshy mass at the back of the testicles,” Modern Latin, literally “that which is on the testicles,” from Greek epididymis, a word probably coined by Greek anatomist Herophilus (c.300 B.C.E.) from epi “on” (see epi-) + didymos “testicle,” literally “double, twofold” (adj.). “To save his Epididamies” [Richard Brome, “The Court Beggar,” 1652].

epididymis ep·i·did·y·mis (ěp’ĭ-dĭd’ə-mĭs)
n. pl. ep·i·di·dy·mi·des (-mĭ-dēz’)
A long, narrow, convoluted tube in the spermatic duct system that lies on the posterior aspect of each testicle and connects with the vas deferens.