Sonny (noun)

A young boy or man, especially one who is considered to be lively or mischievous.

Origin:

The word sonny is informal diminutive of son, it's often used as a term of endearment for a young boy or a young man.

Examples:

1. He's a real sonny, always into mischief.
2. She affectionately called her grandson "sonny".
3. That sonny of mine is going to be the death of me.
4. Come here, sonny, and give your grandma a hug.
5. I remember when you were just a little sonny running around the house.