Etymology of the English word epididymis
the English word epididymis
derived from the Greek word didmoi (testicles)
derived from the Greek word epididumis, ἐπιδιδυμίς
using the Greek prefix epi-, ἐπι-
derived from the Byzantine Greek word epi, ἐπί (upon; properly, meaning superimposition (of time, place, order, etc.), as a relation of distribution (with the genitive case); over, upon, etc.; of rest (with the dative case) at, on, etc.; of direction (with the accusative case) towards, upon, etc.)
derived from the Greek word didumos, δίδυμος (double, hence alongside the testes)
derived from the Proto-Indo-European root *dwo-
derived from the Greek word dumoi