vas ef·fer·ens 
(ĕfər-ənz, -ə-rĕnz′)
(ĕfər-ənz, -ə-rĕnz′)n. pl. vasa ef·fer·en·ti·a (ĕf′ə-rĕnshē-ə)
Any of a number of small ducts that carry semen from the testis to the epididymis.
[New Latin vās efferēns : vās, duct + Latin efferēns, present participle of efferre, to carry out.]