testis n one of the two male reproductive glands that produce spermatozoa and secrete androgens Usage(s) Examination disclosed an ovary on one side, an ovario-testis on the other. Careful examination showed that the infant had one testis, what looked like a small penis and no uterus or vagina. Careful examination showed that the infant had one testis, what looked like a small penis and no uterus or vagina. Synonym(s) testicle orchis ball ballock bollock nut egg