Balls

Balls are a common slang term, of recent but unknown origin, that refer to a male's genitalia, the testes, which hang low below the penis in the scrotum. These balls are a sign of penis size, the comparison of which is known sometimes as "cock fighting". Balls are a sign of strength, as having a larger penis or having larger balls is often associated with having strength and bravery due to the nature in which the balls of a man matter to him. As a larger penis or larger balls grant a man greater respect, having small balls degrades the male, and says one has "no balls" is a sign of disrespect, and males take it as a challenge. In summary, the size of one's balls in slang terms are a way to test one's strength or bravery.

"Little Willy has no balls."