Astynomos is a fancy Greek word that means "police officer." Just like how your mommy and daddy keep you safe by telling you to look both ways before crossing the street, police officers keep everyone in their community safe.
Imagine there's a big playground with lots of kids playing. Sometimes, the kids might not play nice with each other and start pushing or hitting. If someone gets hurt, it's the astynomos' job to come and make sure everyone is okay. They might talk to the kids to figure out what happened and then make sure the ones who did the pushing or hitting don't do it again.
Astynomos also make sure everyone follows the rules. They might stop cars from driving too fast or making too much noise at night. They might also catch bad guys who have done bad things and make sure they go to a special place where they can't hurt anybody else.
So, astynomos are like superhero helpers who make sure everyone in their community is safe and happy.