uncle
A male relative who is your parent's brother or brother-in-law.
An uncle is your parent's brother, or the husband of your parent's sister (your aunt). If your mom has a brother named Tom, Tom is your uncle. If your dad's sister married someone named James, James is also your uncle.
Uncles often play special roles in families. They might teach you skills your parents don't have time for, like how to fish or fix a bike. They might joke around with you more freely than your parents do, or share stories about what your mom or dad was like as a kid. Some uncles live nearby and see you often, while others might live far away and visit during holidays.
In many cultures, people also use uncle as a respectful way to address older men who are close family friends, even if they're not actually related by blood or marriage. A child might call their parents' best friend “Uncle Mike” as a sign of affection and respect.
The phrase cry uncle means to give up or admit defeat, like when you're wrestling with a friend and finally say “uncle!” to make them stop. And Uncle Sam is a nickname for the United States government, often depicted as a tall man with a white beard wearing red, white, and blue.