from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun One of the paired male reproductive organs that produce spermatozoa and male sex hormones in humans and other vertebrates.
  • noun An analogous gland in an invertebrate animal, such as a flatworm or a mollusk.

from The Century Dictionary.

  • noun A testicle.
  • noun Some rounded formation likened to a testicle: as, the testes of the brain.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Anat.) A testicle.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun anatomy A testicle of a vertebrate
  • noun biology An analogous gland in invertebrates such as the hydra

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun one of the two male reproductive glands that produce spermatozoa and secrete androgens


from The American Heritage® Dictionary of the English Language, 4th Edition

[Latin, witness, testis; see testify.]


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  • The receptors are everywhere, but the testis is exquisitely sensitive to the drug.

    For Mice and Men: Male Contraceptives Successful in Rodents | Impact Lab 2007

  • From my own observations, I am led to believe that no such muscular structure as a gubernaculum exists, and therefore that the descent of the testis is the effect of another cause.

    Surgical Anatomy Joseph Maclise

  • The lateral surface, head and tail of the epididymis are free and covered by the serous membrane; the body is also completely invested by it, excepting along its posterior border; while between the body and the testis is a pouch, named the sinus of the epididymis (digital fossa).

    XI. Splanchnology. 3c. The Male Genital Organs 1918

  • The one above the testis is the plica vascularis, and contains ultimately the internal spermatic vessels; the one below, the plica gubernatrix, contains the lower part of the gubernaculum, which has now grown into a thick cord; it ends below at the abdominal inguinal ring in a tube of peritoneum, the saccus vaginalis, which protrudes itself down the inguinal canal.

    XI. Splanchnology. 3. The Urogenital Apparatus 1918

  • -- The male reproductive element of animals is formed by an organ called the testis, or testicle, of which each male possesses two.

    Plain facts for old and young : embracing the natural history and hygiene of organic life. 1877

  • The testis is a pretty awesome organ, comprised mainly of a bunch of coiled loops called seminiferous tubules.

    ScienceBlogs Channel : Life Science Scicurious 2010

  • The sperm starts in the male gonad, otherwise known as the testis, and various other things more suited for the locker room than this esteemed blog.

    ScienceBlogs Channel : Life Science Scicurious 2010

  • SRY = Sex-determining region Y - aka testis determining factor = TDF - Causes gonad to differentiate into testes  SRY protein is DNA-binding regulatory protein  Acts as transcription factor  Initiates transcription of cascade of genes necessary for testicular differentiation

    Recently Uploaded Slideshows 2009

  • Juan Pelota footnote from the W-pedia: "The Latin word 'testis', witness, was used in the firmly established legal principle 'Testis unus, testis nullus' one witness equals no witness..."

    Passing the Mantle: The End of the Aughts is Nigh BikeSnobNYC 2009

  • Spermatozoa travel through the lumen of the seminiferous tubules to the rete testis which is basically a big collecting duct that all the seminiferous tubules empty into.

    ScienceBlogs Channel : Life Science Scicurious 2010


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  • The resemblance between testimony, testify, testis, and testicle shows an etymological relationship, but linguists are not agreed on precisely how English testis came to have its current meaning. The Latin testis originally meant "witness," and etymologically means "third (person) standing by": the te- part comes from an older tri-, a combining form of the word for "three," and -stis is a noun derived from the Indo-European root st�?- meaning "stand." How this also came to refer to the body part(s) is disputed. An old theory has it that the Romans placed their right hands on their testicles and swore by them before giving testimony in court. Another theory says that the sense of testicle in Latin testis is due to a calque, or loan translation, from Greek. The Greek noun parastatēs means "defender (in law), supporter" (para- "by, alongside," as in paramilitary and -statēs from histanai, "to stand"). In the dual number, used in many languages for naturally occurring, contrasting, or complementary pairs such as hands, eyes, and ears, parastatēs had the technical medical sense "testicles," that is "two glands side by side." The Romans simply took this sense of parastatēs and added it to testis, the Latin word for legal supporter, witness. (according to american heritage dictionary)

    July 5, 2007