vas deferens

noun vas def·er·ens \ ˈvas-ˈde-fə-rənz , -ˌrenz \

|Updated on: 4 Jun 2018

Definition of vas deferens

plural vasa deferentia play \ˈvā-zə-ˌde-fə-ˈren(t)-sh(ē-)ə\

: a sperm-carrying duct especially of a higher vertebrate that in the human male is a thick-walled tube about two feet (0.61 meters) long that begins at and is continuous with the tail of the epididymis and eventually joins the duct of the seminal vesicle to form the ejaculatory duct

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Recent Examples of vas deferens from the Web

Men also have the option of a vasectomy, which involves cutting the vas deferens to prevent semen from making it from the testicles to the prostate.

— sarah jacoby, SELF, "Hold On Everyone, Male Birth Control Still Isn't Happening Anytime Soon," 22 Mar. 2018
The idea, discovered by biomedical engineer Sujoy Guha of the Indian Institute of Technology, involves injecting a polymer gel into the vas deferens to block sperm, rather than cutting or tying the vas (a vasectomy).

— julia belluz, Vox, "A pill, a gel, and a nonsurgical vasectomy are making their way through clinical trials.," 4 May 2018
Other forms of male birth control in the works include a topical gel, a gel injected into the vas deferens that mimics the effects of a vasectomy, and an injectable hormone combination.

— sarah jacoby, SELF, "Hold On Everyone, Male Birth Control Still Isn't Happening Anytime Soon," 22 Mar. 2018
Vasalgel is a polymer that is injected into the vas deferens, which transports sperm to the ejaculatory ducts.

— hannah flynn, Ars Technica, "More than half a century later, where’s the male pill?," 28 Feb. 2018
The injection requires only one incision to reach the vas deferens, and can be done easily as an outpatient procedure.

— ben panko, Smithsonian, "Contraceptive Gel Called the “IUD For Men” Makes It Through Monkey Trials," 8 Feb. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'vas deferens.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of vas deferens

borrowed from New Latin vās deferens, literally, "downward-conveying vessel"

NEW! Time Traveler

First Known Use: 1578

in the meaning defined above

See Words from the same year

Medical Dictionary

vas deferens

noun vas def·er·ens \ -ˈdef-ə-rənz, -ˌrenz \

medical Definition of vas deferens

plural vasa deferentia play \-ˌdef-ə-ˈren-ch(ē-)ə\

: a sperm-carrying duct especially of a higher vertebrate that in humans is a small but thick-walled tube about two feet (0.6 meter) long formed by the union of the vasa efferentia, is greatly convoluted in its proximal portion, begins at and is continuous with the tail of the epididymis, runs in the spermatic cord through the inguinal canal, and descends into the pelvis where it joins the duct of the seminal vesicle to form the ejaculatory duct — called also ductus deferens, spermatic duct