Euthyphro and Socrates

In this reading Socrates has been indicted with impiety which leads up to the Apology, and is in front of the court house when he meets Euthyphro. His friend who claims to have a comprehensive understanding of all things pious. So Socrates, naturally, begs his friend with the question, "What is piety and impiety?". So the conversation goes on in circles, with Socrates insisting that Euthyphro is explaining examples and characteristics of piety but not with it is itself. Eventually they make a complete circle with the line "Piety....is that which is dearest to the gods." At this point Socrates believes they have missed something and insists that they restart from the Begining. Euthyphro then claims he has business elsewhere and leaves. Interesting, but with the same logic that Socrates uses, you can do the same thing with anything. Does the definition of any noun not consist of characteristics and examples? Can you define "Lamp" without using characteristics like "produces light", "can be turned on an off", and "uses light bulb"?