Testicals
Testes is the plural form of testis, which means testicle.
Testes is the plural form of testis referring to a pair of male reproductive organs.
Testis is the medical anatomical term. Testis/testicles are the same thing. Testis/testicles are responsible for the production of male hormones and sperm. Testis and testicles are NOT the same thing. "Testis" is the singular form and "testes" is its plural. "Testicles" is the plural of "testicle." I'm not as certain of this, but I've come to believe that a testicle is an abnormally small testis.
The singular word of testes is testis.
"Testis" are the plural of the word "teste" which is the reproductive gland in the male vertebrae. It is the source of sperm and is located in the scrotum.
The testis (plural testes) or testicle is the male sex gland.
A testis (plural testes) is a male gonad.
Bridges is the plural form of bridge.
"Beliefs" does not have a plural form, as it is already plural. Beliefs is the plural form of belief.
There is no plural form for the word, countries. This word itself is a plural.
"Groceries" is the plural form of "grocery."
The plural form of "meter" is "meters."