A shegetz is a non-Jewish boy or young man, often with the connotation of being impolite or not well-behaved.
The word shegetz can have a negative feeling, like someone who doesn't follow the rules.
Examples:
He's a shegetz, he doesn't go to our church.
The shegetz was making a lot of noise.
The shegetz didn't listen to his parents.
The shegetz was running around and causing trouble.
The shegetz was so bad, he broke a window!
The shegetz didn't do his homework and got in trouble.