tes·tis
(tĕs′tĭs)n. pl. tes·tes (-tēz) 1. One of the paired male reproductive organs that produce spermatozoa and male sex hormones in humans and other vertebrates.
2. An analogous gland in an invertebrate animal, such as a flatworm or a mollusk.
[Latin, witness, testis; see testify.]
Word History: 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 stā- 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.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
testis
(ˈtɛstɪs) [C17: from Latin, literally: witness (to masculinity)]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
tes•tis
(ˈtɛs tɪs)
n., pl. -tes (-tēz). the male gonad, either of two oval reproductive glands located in the scrotum.
[1675–85; < Latin]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
tes·tis
(tĕs′tĭs) Plural testes (tĕs′tēz) The reproductive organ of male animals, in which sperm and the sex hormones (androgens) are produced. Vertebrates have two testes, which in most animals are contained inside the body. In many mammals, they lie outside the body and are enclosed by the scrotum.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
testis
(or testicle; pl. testes) One of a pair of primary male sex organs that manufacture male sex cells (sperm) .
Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited