- either of the two male reproductive glands, in most mammals enclosed within the scrotum, that produce spermatozoa and the hormone testosteroneAlso called: testis
n.1590s, alteration of testicule (early 15c.), from Latin testiculus, diminutive of testis “testicle” (see testis). The Old English was herþan, probably originally “leather bag” (cf. heorþa “deer-skin”). The commonest slang terms for them in other languages are words that mean “balls,” “stones,” “nuts,” “eggs.” n.
- A testis, especially one contained within the scrotum.
- Either of the testes of a male mammal together with the scrotum that contains it.